List of practice Questions

In a region, steady and uniform electric and magnetic fields are present. These two fields are parallel to each other. A charged particle is released from rest in this region. The path of the particle will be a
An object is thrown vertically upwards. At its maximum height, which of the following quantity becomes zero?
The self-induced emf of a coil is 25 volts. When the current in it is changed at uniform rate from 10A to 25 A in 1s, the change in the energy of the inductance is:
Alternating current cannot be measured by a D.C. ammeter because
The magnetic field of a plane electromagnetic wave is given by: \[ \vec{B} = 2 \times 10^{-8} \sin \left(0.5 \times 10^3 x + 1.5 \times 10^{11} t \right) \hat{j} \, {T}. \] {The amplitude of the electric field would be:}
An ideal gas is expanding such that \( P T^3 = {constant} \). The coefficient of volume expansion of the gas is:
Two light beams of intensities in the ratio of 9 : 4 are allowed to interfere. The ratio of the intensity of maxima and minima will be:
The de Broglie wavelength of a proton and \( \alpha \)-particle are equal. The ratio of their velocities is:
The recoil speed of a hydrogen atom after it goes from \( n = 5 \) state to \( n = 1 \) state will be:
Which of the following figure represents the variation of \( \ln \left( \frac{R}{R_0} \right) \) with \( \ln A \) (If \( R \) is the radius of a nucleus and \( A \) is its mass number)?
Zener breakdown occurs in a p − n junction having p and n both:
If \( E \) and \( H \) represent the intensity of electric field and magnetizing field respectively, then the unit of \( \frac{E}{H} \) will be:
A stone of mass \( m \), tied to a string is being whirled in a vertical circle with a uniform speed. The tension in the string is:
A particle is moving with a velocity \( \vec{v} = K (y \hat{i} + x \hat{j} )\), where \( K \) is a constant. The general equation for its path is:
The magnetic moment of an electron (e) revolving in an orbit around nucleus with an orbital angular momentum is given by:
Angular momentum of the particle rotating with a central force is constant due to
The escape velocity of a body depends upon mass as:
If two soap bubbles of different radii are connected by a tube:
The focal length \( f \) is related to the radius of curvature \( r \) of the spherical convex mirror by:

A thermodynamic system is taken from an original state D to an intermediate state E by the linear process shown in the figure. Its volume is then reduced to the original volume from E to F by an isobaric process. The total work done by the gas from D to E to F will be:
 

A vertical electric field of magnitude \( 4.9 \times 10^5 \, {N/C} \) just prevents a water droplet of a mass \( 0.1 \, {g} \) from falling. The value of charge on the droplet will be: (Given \( g = 9.8 \, {m/s}^2 \))

In the circuit shown in the figure, the total charge is \( 750 \, \mu C \) and the voltage across capacitor \( C_2 \) is \( 20 \, {V} \). Then the charge on capacitor \( C_2 \) is:
 

For a transistor, \( \alpha \) and \( \beta \) are given as \( \alpha = \frac{I_C}{I_E} \) and \( \beta = \frac{I_C}{I_B} \). Then the correct relation between \( \alpha \) and \( \beta \) will be:
A current \( I \) flows along the length of an infinitely long, straight, thin-walled pipe. Then:
When you walk through a metal detector carrying a metal object in your pocket, it raises an alarm. This phenomenon works on: