List of top Physics Questions

The equation of AC voltage is \( E = 220 \sin(\omega t + \frac{\pi}{6}) \) and the AC current is \( I = 10 \sin(\omega t + \frac{\pi}{6}) \). The average power dissipated is

A current \( I \) flows in the anticlockwise direction through a square loop of side \( a \) lying in the \( xoy \)-plane with its center at the origin. The magnetic induction at the center of the square loop is given by

A particle of charge \( q \) and mass \( m \) moves in a circular orbit of radius \( r \) with angular speed \( \omega \). The ratio of the magnitude of its magnetic moment to that of its angular momentum depends on

A long straight wire of radius \( R \) carries current \( i \). The magnetic field inside the wire at distance \( r \) from its centre is expressed as:

Two resistances equal at \( 0^\circ \, \text{C} \) with temperature coefficient of resistance \( \alpha_1 \) and \( \alpha_2 \) joined in series

Current density varies with radial distance \( r \) as \( J = a r^2 \), in a cylindrical wire of radius \( R \). The current passing through the wire between radial distance \( R/3 \) and \( R/2 \) is

A potentiometer circuit shown in the figure is set up to measure emf of cell E. As the point P moves from X to Y, the galvanometer G shows deflection always in one direction, but the deflection decreases continuously until Y is reached. The balance point between X and Y may be obtained by

An iron rod of length 2m and cross-sectional area of 50mm² stretched by 0.5mm, when a mass of 250 kg is hung from its lower end. Young’s modulus of iron rod is

A solid sphere of radius \( R \) carries a uniform volume charge density \( \rho \). The magnitude of electric field inside the sphere at a distance \( r \) from the centre is

Two point dipoles \( \mathbf{p_k} \) and \( \mathbf{L_k} \) are located at \( (0,0,0) \) and \( (1m, 0, 2m) \) respectively. The resultant electric field due to the two dipoles at the point \( (1m, 0, 0) \) is

Let the energy of an emitted photoelectron be \( E \) and the wavelength of incident light be \( \lambda_0 \). What will be the change in \( E \) if \( \lambda_0 \) is doubled?

Which statement is correct for the given circuit?

A metallic bar is heated from \(0^\circ \, \text{C}\) to \(100^\circ \, \text{C}\). The coefficient of linear expansion is \(10^{-5} \, \text{K}^{-1}\). What will be the percentage increase in length?

For what value of \( A \), \( B \), and \( C \), the output \( Y = 1 \)?

If the wavelength is brought down from 6000 Å to 4000 Å in a photoelectric experiment then what will happen?

Two solenoids are given – 1st has 1 turn per unit length and 2nd has \(n\) turns per unit length. Ratio of magnetic fields at their centres is

A positively charged particle is placed near an infinitely long straight conductor where there is zero gravity. Then

In given circuit, all resistances are of \( 1 \, \Omega \). Current flowing through ammeter is

If the terminal speed of a sphere of gold (density \(19.5 \, \text{g/cm}^3\)) is \(0.2 \, \text{m/s}\) in a viscous liquid (density \(1.5 \, \text{kg/m}^3\)), find the terminal speed of a sphere of silver (density \(10.5 \, \text{g/cm}^3\)) of the same size in the same liquid.

In shown fig, the circular loop of wire is moved with velocity towards the infinite current carrying wire. Then

For a current carrying inductor, emf associated is 20mV. Now, current through it changes from 6A to 2A in 2s. The coefficient of mutual inductance is

The wavelength of an electron for transition from a state \(n_1\) to \(n_2\) is \( \frac{9}{8R} \). Which of the following wavelengths is possible for a transition from \(n_2\) to \(n_1\)?

Holography is based on phenomenon of

A square current carrying loop is changed to a circular loop in time \( t_1 \). Then

In Wheatstone bridge, 4 resistors \( P = 10 \, \Omega \), \( Q = 5 \, \Omega \), \( R = 4 \, \Omega \), \( S = 4 \, \Omega \) are connected in cyclic order. To ensure no current through galvanometer,