List of top Physics Questions

An object is placed $ 30\, cm $ in front of a convex lens of focal length $ 20\, cm $. Find the position of the image.
Calculate the de Broglie wavelength of an electron moving with velocity $ 6 \times 10^6 \, m/s $. (Mass of electron $ m = 9.11 \times 10^{-31} \, kg $, Planck's constant $ h = 6.626 \times 10^{-34} \, Js $)
A resistor of resistance $ 10\, \Omega $ is connected across a $ 20\, V $ battery. Calculate the current flowing through the resistor.
The rate constant $ k $ of a reaction doubles when the temperature is raised from 300 K to 310 K. Calculate the activation energy $ E_a $ of the reaction. (Use $ R = 8.314 \, J/mol\cdot K $)
How much heat is required to raise the temperature of $ 2 \, kg $ of water from $ 20^\circ C $ to $ 80^\circ C $? (Specific heat capacity of water = $ 4200 \, J/kg^\circ C $)
A particle is projected vertically upward with an initial velocity of $ 20 \, m/s $. Calculate the maximum height reached by the particle.
A particle starts from rest and accelerates uniformly at 4 m/s\(^2\). What is the distance covered in the 5th second?
A current of 3 A flows through a resistor of resistance 4 Ω for 2 minutes. The heat produced is:
Two charges of +3 μC and –3 μC are placed 2 cm apart in air. What is the electric potential energy of the system? (Take \( k = 9 \times 10^9 \) Nm\(^2\)/C\(^2\))
Three resistors of $ 2\, \Omega $, $ 3\, \Omega $, and $ 6\, \Omega $ are connected in parallel. What is the equivalent resistance of the combination?
If a force of $ 10 \, \text{N} $ displaces a body by $ 5 \, \text{m} $ in the direction of the force, the work done is:
A block of mass $ 5\, \text{kg} $ is placed on a rough horizontal surface. A horizontal force of $ 25\, \text{N} $ is applied. If the coefficient of friction is $ 0.4 $, what is the acceleration of the block? (Take $ g = 10\, \text{m/s}^2 $)
Water flows through a horizontal pipe with a velocity of 2 m/s. The cross-sectional area of the pipe reduces to half. What is the velocity of water in the narrower section?
The wavelength of a photon is 500 nm. Calculate its energy. (Planck’s constant \( h = 6.63 \times 10^{-34} \, \text{J·s} \), speed of light \( c = 3 \times 10^8 \, \text{m/s} \))
A wire of length 0.5 m carrying a current of 3 A is placed in a magnetic field of 2 T perpendicular to the wire. What is the force on the wire?
A solid sphere of mass 2 kg and radius 0.5 m rolls without slipping down an inclined plane of height 3 m. What is its speed at the bottom? (Take \( g = 9.8\, \text{m/s}^2 \))
A light wave of wavelength 600 nm passes from air into a medium with refractive index 1.5. What is the wavelength of light in the medium?
An ideal gas expands from 2 L to 6 L at a constant temperature of 300 K. Calculate the work done by the gas if pressure remains constant at 2 atm. (1 atm = $1.013 \times 10^5$ Pa)
How much heat is required to raise the temperature of \( 2 \, \text{kg} \) of water from \( 25^\circ C \) to \( 75^\circ C \)? (Specific heat capacity of water \( c = 4200 \, \text{J/kg}^\circ C \))
A rod of length $ 5L $ is bent at a right angle, keeping one side length as $ 2L $. The position of the centre of mass of the system (Consider $ L = 10 $ cm):
Two harmonic waves moving in the same direction superimpose to form a wave $ x = a \cos(1.5t) \cos(50.5t) $ where $ t $ is in seconds. Find the period with which they beat (close to the nearest integer):
A particle is in uniform circular motion. The equation of its trajectory is given by \( x = 2t^2 - 3t + 5 \), where \( x \) and \( y \) are in meters. The speed of the particle is 2 m/s. When the particle attains the lowest \( y \)-coordinate, the acceleration of the particle is (in \( \text{m/s}^2 \)):
A charge \( -6 \, \mu C \) is placed at the center B of a semicircle of radius 5 cm, as shown in the figure. An equal and opposite charge is placed at point D at a distance of 10 cm from B. A charge \( +5 \, \mu C \) is moved from point C to point A along the circumference. Calculate the work done on the charge.
A charge −6µC is placed
A body of mass 500 gram is rotating in a vertical circle of radius 1 m. What is the difference in its kinetic energies at the top and the bottom of the circle?
In an LC circuit, the inductance \( L \) is \( 2 \, \text{H} \) and the capacitance \( C \) is \( 4 \, \mu\text{F} \). What is the frequency of oscillation of the circuit?