Mechanics, electricity, light, thermodynamics and numerical problems
Learn the exact definition of 1 Ampere (the SI unit of electric current). Understand the relationship between charge, current, and time.
Learn the exact value of 1 AMU (Atomic Mass Unit) in kilograms and grams. Understand why AMU is used to measure atomic and molecular masses.
Learn what 1 Joule is equal to in Physics. 1 J = 1 N·m = 1 kg·m²/s². Understand energy conversions to calories, eV, and ergs for Class 9 and Class 11.
1 kilowatt (kW) is equal to 1000 watts (W) or 1000 joules per second (J/s). Learn the conversion with examples and applications.
1 kWh (kilowatt-hour) is equal to 3,600,000 joules (3.6 MJ). Learn the conversion formula, derivation, and practical examples of kWh.
1 micron (micrometre, μm) is equal to 0.001 mm. Learn the conversion between microns, millimetres, metres, and nanometres with examples.
1 nanometre (nm) = 10⁻⁹ metres = 10 angstroms = 1000 picometres. Complete nanometre unit conversion table with examples from physics and chemistry.
Learn the exact definition of 1 Newton (unit of force) and 1 Horsepower (unit of power). Understand their formulas and everyday examples.
Find out exactly what 1 nm is equal to. Learn the conversion between nanometers (nm), meters (m), centimeters (cm), and angstroms.
Learn what 1 Watt equals in Physics. 1 W = 1 J/s = 1 kg·m²/s³. Understand power unit conversions to horsepower and kilowatt for Class 10 Physics.
37.6°C is equal to 99.68°F. Use the formula °F = (°C × 9/5) + 32. A temperature of 37.6°C indicates a mild fever in the human body.
38.2°C is equal to 100.76°F. Use the formula °F = (°C × 9/5) + 32. A temperature of 38.2°C is a moderate fever above the normal 37°C.
38.5°C is equal to 101.3°F. Use the formula °F = (°C × 9/5) + 32. A temperature of 38.5°C is a moderate fever requiring medical attention.
A biker rides 700m north then 300m east. Displacement = 100√58 m ≈ 761.6 m at 23.2° east of north. Distance = 1000 m. Step-by-step vector solution.
A body at rest may have potential energy and acceleration. It has zero velocity, zero momentum, and zero kinetic energy. It cannot have velocity or momentum.
Learn the definition of absolute temperature. Understand absolute zero, the Kelvin scale, and how it relates to molecular kinetic energy in physics.
When a cabin is moved up an inclined plane, the force required is mg sinθ + friction force, and work done equals force × displacement along the incline.
Learn the dimensional formula of acceleration [M0 L1 T-2]. Understand how to derive it using velocity and time.
Learn the formula for acceleration due to gravity (g = GM/R²). Understand the difference between small 'g' and capital 'G', and its value on Earth.
Learn the critical difference between accuracy and precision in physics and data measurement. Understand using the dartboard analogy.
What is the full form of AC? AC stands for Alternating Current. Learn the difference between AC and DC, their uses, and why homes use AC power.
Learn the principle, working and diagram of an AC Generator. Understand electromagnetic induction, slip rings, and brushes in Class 10/12 Physics.
An air bubble in an ice cube acts as a diverging lens and appears bright white due to total internal reflection at the ice-air interface. Critical angle of ice ≈ 49.8°.
Work done by a labourer moving a loaded cart equals force × displacement × cosθ. If the force is perpendicular to displacement, work done is zero.
A metallic sphere weighs 3 kg in air and 2.5 kg in water. Density = 6000 kg/m³ = 6 g/cm³. Step-by-step Archimedes principle solution.
When an electron moves towards the observer, the magnetic field is clockwise (viewed from front). Use the left-hand rule or reverse right-hand rule for electrons.
Learn about the aneroid barometer, an instrument used to measure atmospheric pressure without using liquid mercury. Perfect for geography and physics students.
Learn the definition of the angle of friction. Understand the formula tan θ = μ, relation with the coefficient of friction, and angle of repose.
Learn the dimensional formula of angular momentum. Derive it step by step and understand its SI unit.
A planet moving around a star follows Kepler's laws. Gravitational force provides centripetal force. T² ∝ R³ (Kepler's third law). Learn orbital speed and period.
Learn the main applications of Gauss's theorem in electrostatics. Calculate electric fields for infinitely long wires, infinite plane sheets, and spherical shells.
When a proton moves along a horizontal line towards the observer, the magnetic field lines form anticlockwise circles around its path, by the right-hand rule.
When a siren is blown in a workshop, it produces sound waves. If the siren moves, the Doppler effect causes frequency change. Sound travels at 343 m/s in air.
What is atmospheric refraction? Learn how the bending of light by Earth's atmosphere causes the twinkling of stars and early sunrise. Class 10 Science.
Understand Avalanche Breakdown in semiconductor diodes. Learn how high reverse voltage causes collision ionization and a massive surge in reverse current.
Learn the average acceleration formula: a = (v - u) / t. Understand initial and final velocity, SI units, and how to solve Class 9 and 11 physics problems.
Learn the formula for average velocity in physics. Understand the difference between average speed and average velocity with clear examples.
A wooden block on an inclined plane is in equilibrium when mg sinθ equals friction force μmg cosθ. The block slides when tanθ > μ (coefficient of friction).
A barometer is used to measure atmospheric pressure. Invented by Torricelli in 1643. Normal pressure = 760 mm Hg = 1 atm = 101.325 kPa. Types: mercury, aneroid.
Learn what a BC547 transistor is in physics and electronics. Understand how this common NPN bipolar junction transistor works as a switch and an amplifier.
Learn about the biconvex lens. Understand its converging properties, focal length, ray diagrams, and real-world uses like magnifying glasses and human eyes.
Learn about Ganymede, the biggest natural satellite (moon) in the solar system. Discover facts about Jupiter's giant moon, its size, and its magnetic field.
Learn how a bimetallic strip works using the principle of thermal expansion. Discover its applications in thermostats, fire alarms, and circuit breakers.
Learn how to derive the dimensional formula of the Boltzmann constant (k). Find its SI unit, numerical value, and significance in thermodynamics.
For a complete thermodynamic cycle, ΔU = 0, so heat supplied equals work done: Q = W. Use P-V diagram area to find net work done in the cycle.
Learn what Canal Rays (Anode Rays) are in atomic structure. Understand their discovery by Goldstein and their key properties.
Yes, water contracts on heating from 0°C to 4°C — called anomalous expansion of water. Maximum density at 4°C = 1000 kg/m³. Full explanation with examples.
A capacitor of capacitance C charged to V₀: charge Q = CV₀, energy stored U = ½CV₀². Two-capacitor problems, energy loss, Class 12 Physics explained.
When a ceiling fan is switched off, it decelerates gradually due to friction torque. Angular velocity decreases over time — Newton's first law of rotation and angular deceleration explained.
Learn the definition of centre of curvature for spherical mirrors. Understand its relationship with the radius of curvature and pole.
Learn the CGS unit of force (Dyne). Understand the difference between the CGS and SI systems, and how to convert Dynes to Newtons (1 N = 10^5 dynes).
Learn the characteristics of a shadow in physics. Understand why shadows are always black, how their size changes, and what 3 things are needed to form one.
The charge of an alpha particle is +2e = +3.2 × 10⁻¹⁹ C. An alpha particle consists of 2 protons and 2 neutrons, giving it a charge of +2 elementary charges.
Learn the exact value of the charge of one electron. Discover Millikan's oil drop experiment and the concept of elementary charge in physics.
Learn about the chemical effects of electric current. Understand electrolysis, electroplating, and how electricity causes chemical changes in liquids.
Learn the physics behind what happens if the length of a clock pendulum increases by 0.2 percent. Understand the time period error formula (dt/t = 1/2 dl/l).
Learn about the coefficient of restitution (e) in collisions. Understand its formula, range (0 to 1), and difference between elastic and inelastic collisions.
Learn about coherent sources of light in physics. Understand why two independent bulbs cannot produce interference patterns, but lasers can.
Understand whether a concave mirror is converging or diverging. Learn how it reflects parallel light rays to a single focal point.
Explore practical examples of concave mirrors in daily life. Learn why they are used in shaving mirrors, headlights, and telescopes.
Learn the difference between concave and convex lenses in physics. Understand converging vs diverging light, focal points, and uses in spectacles and magnifying glasses.
Understand the key differences between concave and convex spherical mirrors. Learn their shapes, image formations, and daily life uses.
Learn how to make a kaleidoscope. Understand its construction using three rectangular mirrors and the principle of multiple reflections.
Learn what a converging mirror is in physics. Understand how concave mirrors focus light to a single point and explore their uses in daily life.
Coulomb's law in vector form: F = kq₁q₂r̂/r². The force acts along the line joining the charges. Like charges repel, unlike charges attract.
Understand the concepts of Crest and Trough in wave physics. Learn how they define amplitude and wavelength in transverse waves.
Learn the de Broglie Hypothesis in physics. Understand the dual nature of matter, matter waves, and the de Broglie wavelength formula (λ = h/mv).
Learn the definition of 1 Dioptre (1D). Understand the formula for the power of a lens and its relation to focal length in meters.
Learn the exact scientific definition of 1 Joule of work in physics. Understand the formula W = F x S and how force and displacement create work.
Learn the exact definition of 1 Joule of work. Understand the relationship between force (Newtons), displacement (metres), and energy (Joules).
What is absolute temperature? Learn the definition of absolute zero (0 Kelvin / -273.15°C) and the Kelvin temperature scale.
Learn the definition of Anisotropy in physics and chemistry. Understand why crystalline solids show different physical properties in different directions.
Learn the definition of atmospheric pressure. Understand how the weight of the air exerts pressure on the Earth's surface and how it is measured.
Learn the definition of drift velocity in physics. Understand how free electrons move in a conductor under an electric field and its mathematical formula.
Pitch is the linear distance moved in one complete rotation of the screw. Least Count = Pitch/Number of divisions on circular scale. Screw gauge and Vernier caliper explained.
Learn the exact scientific definition of Potential Difference (Voltage). Understand the formula, the SI unit (Volts), and how it acts as the driving force of electricity.
Learn how to define the SI unit of electric current. Understand the definition of 1 Ampere using the formula I = Q/t for physics exams.
Learn the definition of Uniform Circular Motion. Understand why it is an accelerated motion even when the speed is constant, with real-life examples.
Learn the step-by-step derivation of the kinetic energy formula (K.E. = 1/2 mv^2) using Newton's laws of motion and the work-energy theorem.
Learn the key differences between an Ammeter and a Voltmeter. Understand how they are connected in a circuit (series vs parallel) and what they measure.
Convex lens is thicker in the middle and converges light. Concave lens is thinner in the middle and diverges light. Full comparison with uses and power signs.
Learn the key differences between conductors and insulators in physics. Understand the role of free electrons with clear examples of each material.
Difference between distance and displacement — distance is the total path length (scalar), displacement is the shortest straight-line distance from start to end (vector).
Learn the exact scientific differences between Evaporation and Boiling. Understand surface phenomena vs bulk phenomena, temperature requirements, and cooling effects.
Learn the difference between small 'g' (Acceleration due to gravity) and capital 'G' (Universal Gravitational Constant).
Speed is scalar (distance/time); velocity is vector (displacement/time). Speed is always positive; velocity can be negative. Average speed ≥ average velocity.
Tungsten: pure metal, mp 3422°C, used in bulb filaments. Nichrome: Ni-Cr alloy, high resistivity 110×10⁻⁸ Ω·m, used in heating elements. Key differences explained.
Learn the least count of a digital vernier caliper. Understand how accurate it is (0.01 mm) compared to a manual caliper and how it works.
Learn how to derive the dimensional formula of acceleration [M0 L1 T-2]. Step-by-step physics derivation using velocity and time.
Dimensional formula of angular momentum is [ML²T⁻¹]. Derived from L = mvr or L = Iω. SI unit: kg·m²/s or J·s. Derivation with steps and explanation.
Learn how to derive the dimensional formula of electrical Capacitance [M-1 L-2 T4 A2]. Understand the step-by-step derivation using C = Q/V.
Learn how to derive the dimensional formula of density. Understand its SI unit and importance in Class 11 Physics.
Learn the dimensional formula of electric charge. Understand how it is derived using current and time ([M0 L0 T1 A1]) for Class 11 Physics.
Learn how to derive the dimensional formula of the electric field. Step-by-step calculation using force and charge.
Dimensional formula of Energy is [ML²T⁻²]. Same as Work (W = F×d). SI unit is Joule (J). Full derivation and all forms of energy.
Dimensional formula of Force is [MLT⁻²]. Derived from F = ma. SI unit is Newton (N). Full derivation and dimensional analysis explained.
Dimensional formula of G (gravitational constant) is [M⁻¹L³T⁻²]. Derived from F = Gm₁m₂/r². Value of G = 6.674 × 10⁻¹¹ N·m²/kg².
Learn the dimensional formulas of impulse and linear momentum. Prove mathematically why both have the exact same dimensions.
Dimensional formula of Planck's constant h is [ML²T⁻¹]. Derived from E = hν. Value: 6.626×10⁻³⁴ J·s. SI unit is Joule-second (J·s).
Learn how to derive the dimensional formula of Power. Step-by-step derivation using Work and Time.
Dimensional formula of power is [ML²T⁻³]. Derived from P = W/t or P = Fv. SI unit: Watt (W) = J/s. Full derivation with examples.
Dimensional formula of Pressure is [ML⁻¹T⁻²]. Derived from P = F/A. SI unit is Pascal (Pa). Full derivation with examples.
Learn how to derive the dimensional formula of electrical resistance using Ohm's Law and the definition of electric potential.
Learn the dimensional formula of surface tension. Step-by-step derivation and understanding of its SI unit.
Learn the basic dimensional formula of velocity and acceleration. The starting point for all kinematics and dynamics dimensional analysis.
Learn how to derive the dimensional formula of work. Understand why work, energy, and torque share the same dimensions in physics.
Learn how to derive the dimensional formula of Young's Modulus [M1 L-1 T-2]. Understand the concepts of Stress and Strain in Physics.
Learn the exact dimensional formula of the Coefficient of Viscosity (η). Understand the step-by-step derivation using Stokes' Law and Newton's formula for fluid friction.
Learn how to derive the dimensional formula of the Electric Field [M1 L1 T-3 A-1]. Understand the formula E = F/q step-by-step for Class 11 Physics.
Learn the exact dimensional formula of Force in physics. Understand how to derive [M¹ L¹ T⁻²] using Newton's Second Law of Motion (F = ma).
Learn the exact dimensional formula of the Universal Gravitational Constant (Capital G) in physics. Understand the step-by-step derivation using Newton's Law of Gravitation.
Learn the exact dimensional formula of small 'g' (Acceleration due to gravity) in physics. Understand why its dimension is identical to normal acceleration [L¹ T⁻²].
Learn the exact dimensional formula of the Magnetic Field (B) in physics. Understand the step-by-step derivation using the Lorentz Magnetic Force formula (F = qvB).
Learn the exact dimensional formula of Electrical Resistance in physics. Understand the step-by-step mathematical derivation using Ohm's Law (V = IR).
Learn about the major disadvantages of friction in physics. Understand how it causes wear and tear, wastes energy, and generates unwanted heat in machines.
Learn the concept and formula for Displacement Current (Id) in physics. Understand how Maxwell corrected Ampere's law using changing electric fields.
Learn what a Distomat is used for in civil engineering and physics. Discover how this EDM device uses infrared lasers to measure massive distances instantly.
Learn the major limitations and drawbacks of Rutherford's atomic model. Understand why his model failed to explain the stability of the atom using Maxwell's theory.
Learn what a dry cell is. Discover the internal structure, including the carbon rod and zinc casing, and how it uses chemical paste to generate electricity.
Learn the formula for Efficiency in physics. Understand the ratio of useful work output to total energy input, and why no machine is 100% efficient.
Learn Einstein's Photoelectric Equation in detail. Understand the formula KE = hν - φ, the concept of work function, threshold frequency, and how it proved the particle nature of light.
Learn how an electric bell works. Understand the circuit diagram, the role of the electromagnet, the armature, and the hammer in creating the ringing sound.
Learn what an electric cell is. Understand the definition, how a chemical cell converts chemical energy to electrical energy, its components, and types.
Electric field intensity E = F/q (force per unit charge). SI unit: N/C or V/m. Dimensional formula [MLT⁻³A⁻¹]. Coulomb's law formula and solved examples.
Learn the precise definitions and formulas for Electric Flux and Electromotive Force (EMF). Important electrostatics and current concepts for Class 12.
Learn why the electron volt (eV) is a unit of energy. Find its definition, exact value in Joules, and why it is used in atomic and nuclear physics.
Learn the exact definition of electrostatic potential. Understand the formula, SI unit (Volt), and the concept of bringing a test charge from infinity.
Understand the exact difference between Electromotive Force (EMF) and Potential Difference in an electrical circuit. CBSE Class 12 Physics.
Learn the Equation of Trajectory for projectile motion in physics. Understand the y = x tan(θ) formula and why the path of a projectile is a perfect parabola.
Learn the definition of an Erect Image in physics. Understand the difference between an erect virtual image (like in a plane mirror) and an inverted real image.
Find the best examples of inertia of rest from daily life. Learn how Newton's First Law explains why stationary objects resist any change in their state of rest.
Learn the definition of uniform motion in physics. See clear real-life examples like clock hands, Earth's rotation, and a car on cruise control.
Learn the physics behind why stars twinkle in the night sky but planets do not. Understand the concepts of atmospheric refraction and point-sized light sources.
Learn the definition of Fleming's Left Hand Rule. Understand how to find the direction of magnetic force on a current-carrying conductor in Class 10 Physics.
Fleming's Left Hand Rule: thumb=force/motion, index=magnetic field, middle=current. Used for electric motors. FBI rule explained with diagram and examples.
Learn Fleming's Right-Hand Rule to find the direction of induced current in electric generators. Understand the role of the thumb, forefinger, and middle finger.
Find out if the focal length of a convex lens is positive or negative. Understand the New Cartesian Sign Convention rules for light and optics in Class 10 Physics.
Learn how the electrical force between two point charges varies with distance. Understand Coulomb's Law and the Inverse Square Law in Class 12 Physics.
Is force a scalar or vector quantity? Learn why force is a vector quantity, requiring both magnitude and direction for its complete description.
For two vectors to be equal, they must have the same magnitude (size) and the same direction. Two conditions must both be satisfied for vector equality.
Learn the massive difference between Forward and Reverse Bias in a PN Junction Diode. Discover how a diode acts as a one-way street for electricity in physics.
Learn the difference between a Half Wave and a Full Wave Rectifier. Understand how P-N junction diodes convert AC to DC current in electronics.
Learn about the Heating Effect of Electric Current. Understand Joule's Law of Heating, its formula (H = I²Rt), and real-life applications like heaters and irons.
Learn the exact scientific difference between Heat and Temperature. Understand why heat is total energy (Joules) while temperature is average energy (Kelvin).
Learn what a horseshoe magnet is. Understand why it is shaped like a U, why it is stronger than a bar magnet, and its common uses.
Learn the complete structure of the human eye for Class 10 Physics. Understand the functions of the Retina, Cornea, Lens, and Pupil in simple language.
Hydraulic brakes work on Pascal's Law — pressure applied at one point is transmitted equally throughout. Small force on pedal → large braking force. Full explanation.
Learn the physics behind the classic incandescent lamp (light bulb). Understand how the Tungsten filament works, the role of Argon gas, and its energy efficiency.
Learn the primary differences between interference (superposition of waves from two coherent sources) and diffraction (bending of waves around corners).
An IC engine converts chemical energy of fuel into mechanical energy via combustion inside a cylinder. Types: 2-stroke, 4-stroke. Efficiency 25-40%. Fully explained.
Learn the difference between an Inverting and a Non-Inverting Amplifier in electronics. Understand operational amplifiers (Op-Amps) phase shifts and gain formulas.
Learn what Iron Filings are and how they are massively used in physics experiments to visually see invisible magnetic field lines around a bar magnet.
Learn the difference between Isobaric and Isochoric processes in thermodynamics. Understand constant pressure vs constant volume with simple examples.
Learn the definition of an Isothermal process in Physics (Thermodynamics). Understand Boyle's Law, slow expansion, and why the massive temperature remains completely constant.
Learn what the K Factor (Resistance Coefficient) is in pipeline design. Understand how civil engineers calculate massive pressure drops across pipe valves and elbows.
Learn the exact definition of a Kilowatt Hour (kWh) in physics. Understand how to convert 1 kWh into Joules and how the government calculates your home electricity bill.
Learn why kilowatt hour (kWh) is the commercial unit of electrical energy. Understand the definition, conversion to Joules, and how it appears on your electricity bill.
Latent heat graph shows temperature stays constant during phase change (melting/boiling). Explanation of heating curve, flat portions, and latent heat of fusion and vaporisation.
Learn the two fundamental laws of reflection of light. Understand the angle of incidence, angle of reflection, and the normal line.
Learn the two fundamental Laws of Reflection of light in Physics. Understand the Angle of Incidence, Angle of Reflection, and the Normal line.
LDR (Light Dependent Resistor) resistance decreases when light increases. Made of CdS. Used in street lights, burglar alarms, cameras. Symbol and working explained.
Least count of a standard laboratory thermometer = 1°C. Clinical thermometer = 0.1°F or 0.1°C. Digital thermometers can go to 0.1°C or 0.01°C.
Learn how to calculate the least count of a Vernier Caliper. Get the exact formula and standard values used in Class 11 Physics practicals.
Learn the Left Hand Thumb Rule (Maxwell's Corkscrew Rule). Understand how to determine the direction of the magnetic field around a current-carrying conductor.
Learn how a Lightning Conductor works in physics. Discover how this massive copper rod safely captures 300 million volts of electricity and protects tall buildings.
Learn important Physics concepts: Discover what a Light Year measures, define Magnetic Intensity, and understand Malus's Law of Polarization.
Learn the major limitations of Ohm's Law. Understand why diodes, transistors, and super-heated filaments do not obey V=IR (Non-Ohmic conductors).
Learn the difference between luminous and non-luminous objects in Physics. Discover examples like the Sun, stars, and the Moon.
Learn about luminous and non-luminous objects. Understand the difference between objects that emit their own light and those that reflect light with examples.
Magnetic materials: iron, nickel, cobalt (ferromagnetic). Non-magnetic: copper, aluminium, wood, plastic, brass. Paramagnetic, diamagnetic materials explained with examples.
Learn why sound travels fastest in solid mediums like steel and aluminium. Understand the relationship between particle density and sound propagation.
Find out the dimensional formula for Momentum in physics. Learn the step-by-step derivation using the formula P = m × v.
Complete notes on Motion in a Plane for Class 11 Physics. Covers vectors, projectile motion formulas, and circular motion basics.
Learn what MPa (Megapascal) means in physics and engineering. Understand how it relates to Pascal and where it is used in material strength and pressure.
Learn what Muscular Force is in physics. Understand the difference between contact and non-contact forces, and see real-life examples of muscular force.
Learn who discovered the neutron. Read about Sir James Chadwick's 1932 beryllium bombardment experiment that proved the existence of neutral particles.
Learn real-life examples of Newton's 2nd Law of Motion (F=ma). Understand how mass and acceleration interact in sports, driving, and everyday life.
Learn about Newton, the SI unit of force. Understand its definition, formula, and how it relates to mass and acceleration through Newton's Second Law.
Nichrome wire: alloy of nickel and chromium, high electrical resistance, high melting point. Used in heating elements of electric iron, toaster, heater. Class 10 Physics.
Learn about the Nicol Prism in physics. Understand its construction from calcite crystal, its working principle, and double refraction.
Learn the definition of non-conservative forces in physics. Understand why work done depends on the path taken, unlike conservative forces.
Discover what non-contact forces are. Learn three primary examples: Gravitational force, Magnetic force, and Electrostatic force.
Learn the difference between N-type and P-type extrinsic semiconductors. Understand doping with pentavalent and trivalent impurities.
Calculate the distance and displacement of an object moving in a circle of radius r after half a revolution or a full revolution. Class 9 physics notes.
Learn the exact definition of 1 Coulomb — the SI unit of electric charge. Understand its relationship with Ampere and the charge of an electron.
Learn the exact values of common power units. Find out what 1 Horsepower (HP) is equal to in Watts, and what 1 Unit of Electricity means on your home bill.
Learn the dimensional formula of Planck's Constant (h). Step-by-step derivation using the energy of a photon equation (E = hν).
Understand Max Planck's Quantum Theory of radiation. Learn how energy travels in small, discrete packets called 'Quanta' or 'Photons' rather than a continuous wave.
A point charge is an idealized model where all charge is concentrated at a single point. Learn Coulomb's law, electric field (E=kq/r²), and electric potential (V=kq/r) for Class 12 Physics.
Learn the definition of electric potential difference (Voltage). Understand the formula, SI unit, and why it is the driving force behind electric current.
Learn the formula for Potential Difference (Voltage) in a circuit. Understand the relationship between work done, charge, and the unit Volts.
Power of a lens P = 1/f (f in metres). Unit is Dioptre (D). Convex lens: positive power. Concave: negative. Combination: P = P1 + P2. Examples included.
Learn the formula for the Power of a Lens (P = 1/f). Understand its SI unit (Dioptre), sign conventions for convex and concave lenses.
जानें प्रतिरोध (Resistance) का SI मात्रक क्या है। ओम (Ohm) की परिभाषा और ओम का नियम (Ohm's Law) कक्षा 10 विज्ञान के लिए।
Learn the definition of the principal focus of a concave mirror. Understand how parallel light rays converge at this point after reflection.
Learn the complete Prism formula for Class 12 Physics. Understand the formulas for angle of deviation, minimum deviation, and refractive index of a prism.
Learn the 7 key properties of magnets and the 6 important properties of magnetic field lines for Class 10 Physics. Master these for board exam success.
P-type semiconductor is made by doping Si/Ge with trivalent impurity (Al, B, In). Holes are majority carriers. Compare N-type. Used in diodes, transistors.
Discover the true colour of the Sun. Learn why the sun looks yellow or red from Earth, but is actually pure white when seen from space.
Learn what happens when you mix red and blue colours. Understand the difference between mixing paint (pigments) and mixing light in physics.
Learn the definition of reflection of light. Understand the two laws of reflection (angle of incidence = angle of reflection) with examples.
Find the exact values of the Refractive Index of Air, Vacuum, Water, and Diamond. Understand what refractive index means in Class 10 Light chapter.
Learn the exact refractive index of water (1.33) and why it matters. Understand Snell's Law and how water bends light to make objects appear displaced.
Learn the exact relation between Electric Field and Electric Potential (E = -dV/dr). Understand the potential gradient formula and its physical significance.
Learn the formula for Relative Density in Physics. Understand why it has no unit and how it helps determine if an object will sink or float in water.
Learn the difference between electrical resistance (which depends on length and area) and resistivity (which depends only on the material).
Learn the difference between Reversible and Irreversible processes in Thermodynamics. Simple definitions, conditions, and real-life examples.
Understand Schrödinger's wave mechanics. Discover why, according to Erwin Schrödinger, a particle is equivalent to a 'wave packet'.
Learn the New Cartesian Sign Convention for spherical mirrors and lenses. Understand when focal length (f) and image distance (v) are positive or negative.
Learn the SHM equation x = A sin(ωt + φ). Understand velocity, acceleration, time period formulas and energy in simple harmonic motion for Class 11 Physics.
Learn what a simple microscope is in Physics. Understand how a single convex lens acts as a magnifying glass to see small objects, and explore its common uses.
Learn the SI unit of density. Understand the formula (Mass/Volume), its standard unit (kg/m³), and the CGS unit (g/cm³).
Learn the SI unit of electric charge. Understand what a Coulomb is, the charge of a single electron, and the formula Q = It.
The SI unit of electric current is Ampere (A), named after André-Marie Ampère. 1 Ampere = 1 Coulomb per second. Ohm's law and current formula explained.
The SI unit of length is the metre (m). Defined as the distance light travels in vacuum in 1/299,792,458 seconds. Learn prefixes: km, cm, mm, nm, Å.
The SI unit of pressure is the Pascal (Pa). 1 Pa = 1 N/m². Atmospheric pressure = 101,325 Pa. Learn formula, dimensional formula, and unit conversions.
Learn the SI units of electrical resistance (Ohm), resistivity (Ohm-meter), and capacitance (Farad). Understand their definitions and formulas.
The SI unit of resistivity is ohm-metre (Ω·m). Derived from ρ = RA/L. Definition, formula, dimension, and resistivity values of common materials explained.
Learn the SI unit of time. Understand why the Second (s) is the universal standard for measuring time and how it is scientifically defined.
The SI unit of work is the Joule (J). 1 Joule = 1 Newton × 1 metre. Work = Force × displacement × cos θ. CGS unit is erg; 1 J = 10⁷ erg.
SI unit of acceleration is m/s², distance is metre, heat is joule, speed is m/s, velocity is m/s, weight is newton. Complete SI units table for Class 9–12 Physics.
Memorize important Physics SI Units for exams. Find out the SI unit of Electric Charge (Coulomb), Frequency (Hertz), and Magnetic Flux (Weber).
Solar water heater uses solar energy to heat water. Working: flat plate collector or evacuated tubes absorb sun's energy. Types, benefits, and cost in India explained.
Find out why sound cannot travel through a vacuum. Learn the difference between mechanical waves (Sound) and electromagnetic waves (Light) in Physics.
Get a quick summary of the Class 9 Physics chapter 'Sound'. Learn how sound is produced, longitudinal waves, compression, and rarefaction.
Learn the exact speed of light in air, vacuum, water, and glass. Understand the physics constant 'c' and why light is the fastest thing in the universe.
Learn the exact speed of sound in air (343 m/s at 25°C), water, and steel. Understand how temperature and medium affect the speed of sound.
Learn the crucial difference between Speed and Velocity in physics. Understand why speed is a scalar quantity and velocity is a vector quantity that requires direction.
Stefan's Law: P = σAT⁴. Stefan-Boltzmann constant σ = 5.67×10⁻⁸ W/m²K⁴. Power radiated by a black body is proportional to T⁴. Applications and derivation.
Learn how to derive the dimensional formula of Surface Tension [M1 L0 T-2]. Get step-by-step notes for Class 11 Physics Units and Measurements.
If thermal capacities of two bodies are in ratio C₁:C₂, then for equal heat supplied, temperature rises are in ratio C₂:C₁. Formula: Q = CΔT where C = mc.
Learn the definition of Threshold Frequency in the Photoelectric Effect. Understand why no electrons are emitted below this frequency regardless of light intensity.
Learn the basic formula for Time and Work problems. Includes the concept of efficiency, work done per day, and solved examples for competitive exams.
Learn the definition of Time Period in physics. Understand how it relates to frequency, its formula (T = 1/f), and examples from pendulums and waves.
Learn the formula for the time period of a simple pendulum T=2π√(L/g). Understand what factors affect and do not affect its time period.
Learn the definition of the triple point of water. Understand the exact temperature (273.16 K) and pressure (611.657 Pa) where water exists as solid, liquid, and gas simultaneously.
Two applications: (1) explaining planetary motion and Kepler's laws; (2) calculating mass of the Sun/Earth. Also explains tides, escape velocity, and satellite orbits.
Learn about the two main types of lenses — Convex (converging) and Concave (diverging) — with their properties, uses, and key differences.
Learn the definition of uniform acceleration. Understand the three equations of motion and how to apply them in Class 9 Physics problems.
Learn the SI unit of electrical conductance (Siemens or Mho). Understand its relation to resistance and the formula G = 1/R.
Learn the SI unit of electric flux (Volt-metre or N⋅m²/C). Understand Gauss's Law and how electric flux is calculated through a surface.
Learn the SI unit of heat in physics. Understand the difference between Joules and Calories, and learn the mechanical equivalent of heat conversion formula.
Learn the SI unit of luminous intensity. Understand what the Candela (cd) measures in physics and how it relates to the brightness of a standard candle.
Unit of magnetic flux is Weber (Wb). Also V·s or T·m². Formula: Φ = B·A·cosθ. Dimensional formula [ML²T⁻²A⁻¹]. Faraday's law explained.
Learn the SI unit of speed in physics. Understand why meters per second (m/s) is used globally in science, and how to convert it to km/h for vehicles.
Learn the practical uses of a concave mirror. Understand why they are used as shaving mirrors, in car headlights, and by dentists in Class 10 Physics.
Understand the difference between the valence band and conduction band in Class 12 Physics. Learn how the energy gap determines conductors, semiconductors, and insulators.
Learn Varignon's Theorem in Engineering Mechanics. Understand the principle of moments, the formula, and its application in calculating resultant forces.
Learn the Vernier Caliper least count formula (LC = 1 MSD − 1 VSD). Find the standard least count value of 0.01 mm for Class 11 Physics practicals.
जानें विद्युत धारा (Electric Current) का SI मात्रक क्या है। What is Ampere? कक्षा 10 विज्ञान के लिए एम्पीयर (A) की परिभाषा और सूत्र समझें।
Learn about the Watt-Hour Efficiency of a lead-acid battery. Understand the definition, formula, and the difference between Ampere-hour and Watt-hour efficiency.
Speed of sound in hydrogen at 0°C ≈ 1270 m/s. Wavelength λ = v/f. For 1000 Hz: λ ≈ 1.27 m. Hydrogen has the highest speed of sound among common gases.
Learn about canal rays, discovered by E. Goldstein in 1886. Understand how these positively charged anode rays led to the discovery of the proton.
Learn what Eddy Currents are in Physics (Class 12). Understand Foucault currents, their causes, and read two real-world applications like Magnetic Braking.
Learn what an ammeter measures. An ammeter measures electric current in Amperes. Understand how it is connected in series and ideal resistance.
Learn the meaning of Acceleration due to gravity (g). Discover its standard value on Earth (9.8 m/s²), the physics formula, and how it differs from Capital 'G'.
As angle of incidence increases in a denser medium: refracted ray bends away, reaches 90° at critical angle, then total internal reflection occurs beyond it.
Learn what a lubricant is in physics. Discover how lubricants reduce friction between moving surfaces, preventing wear and tear in machinery.
Learn Ampere's Circuital Law in Electromagnetism. Understand the line integral formula, the permeability of free space (μ₀), and its application for solenoids.
Learn what an ebonite rod is and why it is used in physics. Understand how rubbing an ebonite rod with animal fur creates static electricity and negative charges.
A semiconductor has conductivity between a conductor and insulator. Examples: silicon, germanium. Types: intrinsic and extrinsic (n-type, p-type). Used in transistors and ICs.
Learn what Buoyancy is in Physics. Understand why heavy steel ships float on water, the upward force (Upthrust), and Archimedes' Principle in simple terms.
Learn what Displacement Current is in Class 12 Physics. Understand Maxwell's correction to Ampere's Law and how a changing electric field creates a magnetic field.
Learn what Lateral Inversion is in Physics. Discover why your left hand looks like your right hand in a plane mirror, and the science behind AMBULANCE writing.
Learn what a Physical Quantity is in Physics. Understand the difference between Fundamental and Derived quantities, with examples like mass, length, and velocity.
Learn what Reverberation is in Sound Physics. Understand why empty rooms sound hollow, the difference between an echo and reverberation, and how to reduce it.
Learn what the Scattering of Light is. Understand Rayleigh scattering, the Tyndall effect, and the scientific reason why the sky is blue and sunsets are red.
Learn what the acceleration of free fall is. Understand why g = 9.8 m/s², how it relates to gravity, and its use in kinematic equations for Class 9 Physics.
Learn the SI unit of force in Physics. Understand why the unit is called Newton, its definition from F=ma, and examples of force in daily life for Class 9.
Learn what a virtual image is in Physics. Understand the difference between real and virtual images, which mirrors form them, and examples from daily life.
A diver experiences greater pressure at greater depth. Pressure = P₀ + ρgh. Every 10 m depth adds ~1 atm (101 kPa) of pressure in seawater.
Find out who is known as the father of physics. Learn about the contributions of Galileo Galilei, Isaac Newton, and Albert Einstein to physical sciences.
Learn why sound waves are called mechanical waves in Physics. Understand what a medium is, longitudinal wave nature of sound, and why sound cannot travel in vacuum.
When a Ferris wheel moves downward, your apparent weight decreases: N = m(g − v²/r). The reduced normal force causes a stomach-drop sensation. Centripetal force explained with examples.
Echo is not heard in a classroom because the walls are too close. Minimum distance for echo = 17 m. Most classrooms are 8–10 m — the reflected sound merges with the original.
Learn the formula for work done in an adiabatic process. Understand W = (P1V1 - P2V2)/(γ-1) with derivation, conditions, and examples for Class 11 Physics.
Learn the work function formula in Physics. Understand φ = hν₀, Einstein's photoelectric equation, and threshold frequency for Class 12 Physics.
Find the dimensional formula of Young's Modulus. Y = Stress/Strain gives [ML⁻¹T⁻²]. Learn SI unit, derivation, and formula for Class 11 Physics.