Physics MCQ Questions & Answers [PDF Download]
A carnot engine operates between two thermal reservoirs at temperatures 600 K and 300 K. What is the efficiency of the engine?
A projectile is fired at an angle of 30° with the horizontal with an initial velocity of 100 m/s. What is the maximum height reached by the projectile? (Take g = 10 m/s²)
A uniform solid sphere of radius R and mass M rolls down an inclined plane of height h without slipping. What is its velocity at the bottom?
In a photoelectric effect experiment, the maximum kinetic energy of emitted electrons is 2.5 eV when light of wavelength 400 nm is used. What is the work function of the metal? (Take hc = 1240 eV·nm)
A parallel plate capacitor with plate separation d is filled with a dielectric of dielectric constant K. If the capacitor is connected to a battery of voltage V, what is the energy stored in the capacitor?
A wire of resistance R is stretched to double its length. If the volume remains constant, what is the new resistance?
In Young's double slit experiment, the distance between slits is 0.5 mm and the screen is placed 2 m away. If the wavelength of light used is 600 nm, what is the fringe width?
A uniform magnetic field B = 0.5 T is perpendicular to a circular loop of radius 0.1 m. If the magnetic field is reduced to zero in 0.2 s, what is the induced EMF?
A sound wave travels through air at 340 m/s. If the wave has a frequency of 680 Hz, what is the wavelength?
An electron moves in a circular path of radius 0.01 m in a magnetic field of 0.1 T. What is the speed of the electron? (Take e = 1.6 × 10⁻¹⁹ C, m = 9.1 × 10⁻³¹ kg)
A convex lens of focal length 20 cm forms an image of an object placed 30 cm away. What is the magnification of the image?
A simple pendulum of length 1 m oscillates with small amplitude. What is its time period? (Take g = 10 m/s²)
Two identical charges of +3 μC each are placed 6 cm apart in air. What is the force between them? (Take k = 9 × 10⁹ N·m²/C²)
A particle performs SHM with amplitude 0.1 m and frequency 2 Hz. What is the maximum acceleration?
A ray of light passes from air (n₁ = 1) into glass (n₂ = 1.5) at an angle of incidence of 45°. What is the angle of refraction?
A uniform rod of mass M and length L is pivoted at one end. What is the moment of inertia about the pivot?
An ideal gas undergoes an isothermal expansion at 300 K. If the volume changes from 2 L to 6 L, what is the work done by the gas? (Take R = 8.314 J/mol·K, assume 1 mole of gas)
A conducting sphere of radius 0.1 m carries a charge of 10 μC. What is the electric field at a distance of 0.2 m from the center? (Take k = 9 × 10⁹ N·m²/C²)
A wire loop of area 0.05 m² is placed in a uniform magnetic field. The magnetic flux through the loop changes at a rate of 0.2 Wb/s. What is the induced EMF?
A gas undergoes an adiabatic expansion where the volume doubles. If the initial pressure is 2 atm and γ = 1.4, what is the final pressure?
A mass of 2 kg is attached to a spring with spring constant 200 N/m. If the mass is displaced 0.1 m from equilibrium and released, what is the maximum speed?
A beam of X-rays with wavelength 0.1 nm undergoes Compton scattering. If the scattered X-ray has wavelength 0.1024 nm, what is the scattering angle?
A uniform electric field of 1000 N/C points vertically upward. An electron is projected horizontally with speed 10⁶ m/s. What is the vertical displacement after traveling 0.01 m horizontally?
A uniform solid cylinder of mass M and radius R rolls without slipping down an inclined plane. What fraction of its total kinetic energy is rotational?
A parallel plate capacitor is connected to a 12 V battery and fully charged. If the battery is then disconnected and the plate separation is doubled, what is the new voltage across the capacitor?
A sound wave in air has intensity 10⁻⁶ W/m². What is the sound intensity level in decibels? (Take reference intensity I₀ = 10⁻¹² W/m²)
A hydrogen atom transitions from n=3 to n=2 energy level. What is the wavelength of the emitted photon? (Take R = 1.097 × 10⁷ m⁻¹)
A uniform magnetic field B = 0.2 T exists in a region. A square loop of side 0.1 m moves with velocity 5 m/s perpendicular to the field. What is the motional EMF induced?
A radioactive sample has a half-life of 20 years. What fraction of the original sample remains after 60 years?
A mass m attached to a vertical spring oscillates with amplitude A. At what displacement from equilibrium is the kinetic energy equal to the potential energy?
A conducting rod of length 0.5 m rotates about one end in a uniform magnetic field of 0.4 T. If the rod rotates at 120 rpm, what is the EMF induced between its ends?
Two coherent sources separated by 2 mm produce interference fringes on a screen 3 m away. If the central bright fringe is at the center, what is the path difference at a point 1.5 mm from the center?
A gas expands from 2 L to 6 L against a constant external pressure of 3 atm. How much work is done by the gas? (1 atm = 101.3 kPa)
A uniform beam of length 4 m and mass 20 kg is supported by two pillars placed 1 m from each end. What is the reaction force at each pillar?
A particle in a one-dimensional box of length L has energy E₁ in the ground state. What is the energy of the particle in the third excited state (n=4)?