List of top Physics Questions

A particle of mass 500 g is at rest. It is free to move along a straight line. The power delivered to the particle varies with time according to the following graph:

The figure shows variation of \( R \), \( X_L \), and \( X_C \) with frequency \( f \) in a series LCR circuit. Then for what frequency point is the circuit capacitive?

In an LCR series circuit, the value of only capacitance \( C \) is varied. The resulting variation of resonance frequency \( f_0 \) as a function of \( C \) can be represented as

Depletion region in an unbiased semiconductor diode is a region consisting of

A moving electron produces

The natural logarithm of the activity \( R \) of a radioactive sample varies with time \( t \) as shown. At \( t = 0 \), there are \( N_0 \) undecayed nuclei. Then \( N_0 \) is equal to \([\text{Take} \ e^{7.5}] \)

Water flows through a horizontal pipe of varying cross-section at a rate of 0.314 m³/s. The velocity of water at a point where the radius of the pipe is 10 cm is

For a particle executing simple harmonic motion (SHM), at its mean position:

Electromagnetic waves are incident normally on a perfectly reflecting surface having surface area \( A \). If \( I \) is the intensity of the incident electromagnetic radiation and \( c \) is the speed of light in vacuum, the force exerted by the electromagnetic wave on the reflecting surface is

A thick metal wire of density \( \rho \) and length \( L \) is hung from a rigid support. The increase in length of the wire due to its own weight

The final image formed by an astronomical telescope is

A uniform magnetic field of strength \( B = 2 \, \text{mT} \) exists vertically downwards. These magnetic field lines pass through a closed surface as shown in the figure. The closed surface consists of a hemisphere \( S_1 \), a right circular cone \( S_2 \), and a circular surface \( S_3 \). The magnetic flux through \( S_1 \) and \( S_2 \) are respectively

A luminous point object O is placed at a distance \( 2R \) from the spherical boundary separating two transparent media of refractive indices \( n_1 \) and \( n_2 \), where \( R \) is the radius of curvature of the spherical surface. If \( n_1 = \frac{3}{2} \), \( n_2 = 3 \), and the image is obtained at a distance from P equal to

The ratio of area of first excited state to ground state of orbit of hydrogen atom is

A square loop of side length \( a \) is moving away from an infinitely long current-carrying conductor at a constant speed \( v \) as shown. Let \( x \) be the instantaneous distance between the long conductor and side AB. The mutual inductance \( M \) of the square loop - long conductor pair changes with time \( t \) according to which of the following graphs?

In Young's double slit experiment, an electron beam is used to produce interference fringes of width \( \beta_1 \). Now the electron beam is replaced by a beam of protons with the same experimental setup and same speed. The fringe width obtained is \( \beta_2 \). The correct relation between \( \beta_1 \) and \( \beta_2 \) is

The photoelectric work function for a photo metal is \( 2 \, \text{eV} \). Among the four wavelengths, the wavelength of light for which photoemission does not take place is

Dimensional formula for activity of a radioactive substance is

An electric bulb of 60 W, 120 V is to be connected to a 220 V source. What resistance should be connected in series with the bulb, so that the bulb glows properly?

The upper level of valence band and lower level of conduction band overlap in the case of

Magnetic hysteresis is exhibited by magnetic materials.

Magnetic susceptibility of Mg at 300 K is \( 1.2 \times 10^{-5} \). What is its susceptibility at 200 K?

Which of the following combinations should be selected for better tuning of an LCR circuit used for communication?

A galaxy is moving away from the Earth so that a spectral line at 6000 Å is observed at 6300 Å. Then the speed of the galaxy with respect to the Earth is

In alpha particle scattering experiment, if \( v \) is the initial velocity of the particle, then the distance of closest approach is