List of top Physics Questions

The work done by a gas is maximum when it expands from a volume \( V_1 \) to \( V_2 \), then the expansion is

A diffraction pattern is obtained by using a beam of red light. If the red light is replaced by the blue light, then

The time taken for the amplitude of vibrations of a damped oscillator to drop to 25% of its initial value is \( t \). The time taken for its mechanical energy to drop to 50% of its initial mechanical energy is

A rod is found to be 0.05 cm longer at 40°C than it is at 10°C. The length of the rod at 0°C is (coefficient of linear expansion of the material of the rod = \( 1.5 \times 10^{-5} \, \text{°C}^{-1} \))

A particle is executing simple harmonic motion. If the minimum time taken by the particle to move from extreme position to half of the amplitude is \( t_1 \), and the minimum time taken by the particle to move from mean position to half of the amplitude is \( t_2 \), then

A body of mass 10 g is tied to a string of length 0.4 m and it is whirled in a horizontal plane with a speed of 6 m/s. Then the tension in the string is

Two bodies of masses \( m_1 \) and \( m_2 \) are dropped from two different heights \( h_1 \) and \( h_2 \) respectively. The ratio of the times taken by the two masses to touch the ground is (neglect air resistance)

The magnitude of the external force acting on moving bodies can be known directly by

Three particles of each mass \( m \) are kept at the three vertices of an equilateral triangle. If \( I_1 \) is the moment of inertia of the system of the particles about an axis along one side of the triangle and \( I_2 \) is the moment of inertia of the system of the particles about an axis along the perpendicular bisector of a side, then \( I_1 : I_2 \) is

A person of height 1.6 m is walking away from a lamp post of height 4 m along a straight line on the horizontal ground. The lamp post and the person are always vertical. If the speed of the person is 60 cm/sec, then find the speed of tip point of its shadow with respect to the person in cm/sec.

Resistance of a carbon resistor determined from colour codes is (22000±5%)Ω. The colour of third band must be:

Among the following, the possible nuclear reaction is:

In a transistor amplifier used in CE configuration, the phase difference between input voltage and output voltage is:

The speed of an electron in an orbit of hydrogen atom is \( \frac{1}{274} \) times the speed of light in vacuum. The kinetic energy of the electron in the orbit is:

A changing current in a coil can induce an emf in a nearby coil. This process is:

If the radius of the Earth is \( 6.4 \times 10^6 \, m \) and its magnetic dipole moment is \( 1.3 \times 10^{23} \, Am^2 \), then the magnetic field at the equator is:

The variation of charge \( q \) with time \( t \) on a parallel plate capacitor is given by \( q = q_0 \cos(\omega t) \). The displacement current through the capacitor is:

The de Broglie wavelength of an electron in the first orbit of hydrogen atom is:

Two capacitors of capacities 10 µF and 20 µF are connected in series across a 200 V source. The charged capacitors are disconnected from the source and reconnected in parallel with their positive plates together. The potential difference across each capacitor is:

The charge flowing through a resistance \( R \) varies with time as \( q = at - bt^2 \), where \( a, b \) are positive constants. The total heat produced in \( R \) is:

The resultant amplitude of superposition of two waves \( y_1 = a \cos(\omega t) \) and \( y_2 = a \cos(\omega t + \phi) \) is:

A magnetic field of 1 T is acting on a wire carrying a current of 1 A so that the wire is at rest in air. If the mass of the wire is 100 g, then the length of the wire is:

If the temperature of a gas is increased from 27°C to 927°C, the rms speed is:

A fluid flows through a pipe of diameter 5 cm with a velocity 2 m/s. If the pipe is constricted to a diameter of 3 cm, the velocity of fluid at the constriction is: