List of top Physics Questions

On an average, the number of neutrons and the energy of a neutron released per fission of a uranium atom are respectively

If the frequency of incident light falling on a photosensitive metal is doubled, the kinetic energy of the emitted photoelectron is

The half-life of a radioactive substance is 20 minutes. The time taken between 50% decay and 87.5% decay of the substance will be

The ratio of the surface area of the nuclei \(_{52}\text{Te}^{125}\) to that of \(_{13}\text{Al}^{27}\) is

The apparent flattening of the sun at sunset and sunrise is due to

The polarising angle for a medium is found to be \( 60^\circ \). The critical angle of the medium is

Light of wavelength 5000 \r{A is incident normally on a slit of width $2.5 \times 10^{-4}$ cm. The angular position of second minimum from the central maximum is}

In Young's double slit experiment, to increase the fringe width

An electron of mass \(m_e\) and a proton of mass \(m_p\) are accelerated through the same potential. Then the ratio of their de Broglie wavelengths is

Identify the mismatch in the following

In a plane electromagnetic wave, the electric field of amplitude \( 1 \text{ V m}^{-1} \) varies with time in free space. The average energy density of magnetic field is (in \( \text{Jm}^{-3} \))

Which one of the following is the property of a monochromatic, plane electromagnetic wave in free space?

A conducting ring of radius 1 m kept in a uniform magnetic field B of 0.01 T, rotates uniformly with an angular velocity 100 rad s\(^{-1}\) with its axis of rotation perpendicular to B. The maximum induced emf in it is

A step down transformer increases the input current 4 A to 24 A at the secondary. If the number of turns in the primary coil is 330, the number of turns in the secondary coil is

Identify the correctly matched pair

The polarity of induced emf is given by

If the radius of the dees of cyclotron is \(r\), then the kinetic energy of a proton of mass \(m\) accelerated by the cyclotron at an oscillating frequency \(\nu\) is

In an LCR series circuit, at resonance

A bar magnet of moment of inertia \(9 \times 10^{-5} \text{ kg m}^2\) placed in a vibration magnetometer and oscillating in a uniform magnetic field \(16\pi^2 \times 10^{-5} \text{ T}\) makes 20 oscillations in 15 s. The magnetic moment of the bar magnet is

If a magnetic dipole of moment M situated in the direction of a magnetic field B is rotated by \(180^\circ\), then the amount of work done is

Five cells each of emf E and internal resistance \(r\) send the same amount of current through an external resistance R whether the cells are connected in parallel or in series. Then the ratio \( \left( \frac{R}{r} \right) \) is

The power dissipated in the transmission cables carrying current I and voltage V is inversely proportional to

The magnitude of the magnetic field inside a long solenoid is increased by

A rigid container with thermally insulated walls contains a gas and a coil of resistance 50 \(\Omega\), carrying a current of 1 A. The change in internal energy of the gas after 2 minutes will be

If the ammeter A shows a zero reading in the circuit shown below, the value of resistance R is