List of top Physics Questions

A sample of 1 mole gas at temperature T is adiabatically expanded to double its volume. If adiabatic constant for the gas is \(\gamma=\frac{3}{2}\) , then the work done by the gas in the process is:

The equivalent resistance between A and B is:

A bulb and a capacitor are connected in series across an ac supply. A dielectric is then placed between the plates of the capacitor. The glow of the bulb:

One main scale division of a vernier caliper is equal to m units. If n^th division of main scale coincides with (n + 1)^th division of vernier scale,
the least count of the vernier caliper is:

A heavy iron bar, of weight W is having its one end on the ground and the other on the shoulder of a person. The bar makes an angle \(\theta\) with the horizontal. The weight experienced by the person is:

A galvanometer has a coil of resistance \(200 \, \Omega\) with a full scale deflection at \(20 \, \mu A\). The value of resistance to be added to use it as an ammeter of range (0–20) mA is:

A particle of mass m moves on a straight line with its velocity increasing with distance according to the equation \( v = \alpha \sqrt{x} \), where \(\alpha\) is a constant. The total work done by all the forces applied on the particle during its displacement from \( x = 0 \) to \( x = d \), will be:

Given below are two statements:
Statement (I): When currents vary with time, Newton’s third law is valid only if momentum carried by the electromagnetic field is taken into account. 
Statement (II): Ampere’s circuital law does not depend on Biot-Savart’s law. 
In the light of the above statements, choose the correct answer from the options given below:

An astronaut takes a ball of mass \( m \) from earth to space. He throws the ball into a circular orbit about earth at an altitude of 318.5 km. From earth's surface to the orbit, the change in total mechanical energy of the ball is \( x \frac{GM_em}{21R_e} \). The value of \( x \) is
(take \( R_e = 6370 \, \text{km} \)):

The energy equivalent of 1g of substance is:

The volume of an ideal gas (\( \gamma = 1.5 \)) is changed adiabatically from 5 litres to 4 litres. The ratio of initial pressure to final pressure is:

The dimensional formula of latent heat is:

A light unstretchable string passing over a smooth light pulley connects two blocks of masses \(m_1\) and \(m_2\). If the acceleration of the system is \(\frac{g}{8}\), then the ratio of the masses \(\frac{m_2}{m_1}\) is:

A capacitor is made of a flat plate of area A and a second plate having a stair-like structure as shown in figure. If the area of each stair is \(\frac{A}{3}\) and the height is d, the capacitance of the arrangement is:

A sphere of relative density \( \sigma \) and diameter \( D \) has a concentric cavity of diameter \( d \). The ratio of \( \frac{D}{d} \), if it just floats on water in a tank, is:

A light emitting diode (LED) is fabricated using GaAs semiconducting material whose band gap is 1.42 eV. The wavelength of light emitted from the LED is:

Given below are two statements:
Statement (I): When an object is placed at the centre of curvature of a concave lens, image is formed at the centre of curvature of the lens on the other side.
Statement (II): Concave lens always forms a virtual and erect image.
In the light of the above statements, choose the correct answer from the options given below:

A plane EM wave is propagating along x direction. It has a wavelength of 4 mm. If electric field is in y direction with the maximum magnitude of 60 V m^-1, the equation for magnetic field is:

A particle moving in a straight line covers half the distance with speed 6 m/s. The other half is covered in two equal time intervals with speeds 9 m/s and 15 m/s respectively. The average speed of the particle during the motion is:

A proton, an electron, and an alpha particle have the same energies. Their de-Broglie wavelengths will be compared as:

Three capacitors of capacitances 25 μF, 30 μF and 45 μF are connected in parallel to a supply of 100 V. Energy stored in the above combination is E. When these capacitors are connected in series to the same supply, the stored energy is \(\frac{9}{x} E\)  . The value of x is .................

In the experiment to determine the galvanometer resistance by half-deflection method, the plot of \(\frac{1}{ \theta}\) vs the resistance (R) of the resistance box is shown in the figure. The figure of merit of the galvanometer is .............. ×10^–1 A/division. [The source has emf 2V]

An ac source is connected in given series LCR circuit. The rms potential difference across the capacitor of 20 μF is .............. V.

If three helium nuclei combine to form a carbon nucleus then the energy released in this reaction is .......... × 10^–2 MeV.
(Given 1 u = 931 MeV/c² , atomic mass of helium = 4.002603 u)

A body moves on a frictionless plane starting from rest. If \( S_n \) is the distance moved between \( t = n - 1 \) and \( t = n \) and \( S_{n-1} \) is the distance moved between \( t = n - 2 \) and \( t = n - 1 \), then the ratio \( \frac{S_{n-1}}{S_n} \) is \( \left(1 - \frac{2}{x}\right) \) for \( n = 10 \). The value of \( x \) is _________.