List of top Physics Questions

The temperature of equal masses of three different liquids A, B, and C are 12°C, 19°C, and 28°C respectively. The temperature when A and B are mixed is 16°C and when B and C are mixed is 23°C. The temperature when A and C are mixed is:

The molar specific heats of an ideal gas at constant pressure and volume are denoted by \( C_p \) and \( C_v \), respectively. If \( \gamma = \dfrac{C_p}{C_v} \) and \( R \) is the universal gas constant, then \( C_v \) is equal to:

The current sensitivity of a moving coil galvanometer depends on:

A square loop, carrying a steady current \( I \), is placed in a horizontal plane near a long straight conductor carrying a steady current \( I \), at a distance \( d \) from the conductor as shown in figure. The loop will experience:

Two batteries of emf 4 V and 8 V with internal resistance 1 \( \Omega \) and 2 \( \Omega \) are connected in a circuit with a resistance of 9 \( \Omega \) as shown in the figure. The current and potential difference between the points P and Q are:

In Young's double slit experiment, intensity at a point is \( \dfrac{1}{4} \) of the maximum intensity. Angular position of this point is (separation between slits is \( d \)):

The magnetic field in a travelling electromagnetic wave has a peak value of 20 nT. The peak value of electric field strength is:

The horizontal component of the earth’s magnetic field is \( 3.6 \times 10^{-5} \) tesla where the dip angle is 60°. The magnitude of the earth’s magnetic field is:

The velocity of water in a river is 18 km/hr near the surface. If the river is 5 m deep, find the shearing stress between the horizontal layers of water. The coefficient of viscosity of water is \( 10^{-2} \) poise:

The I-V characteristic of a diode is shown in the figure. The ratio of forward to reverse bias resistance is:

Two coils have a mutual inductance 0.005 H. The current changes in the first coil according to equation \( I = I_0 \sin \omega t \), where \( I_0 = 10A \) and \( \omega = 100\pi \, \text{radian/sec} \). The maximum value of e.m.f. in the second coil is:

The equivalent capacitance between a and b for the combination of capacitors shown in figure where all capacitances are in microfarad is:

The activity of a radioactive sample is measured as 9750 counts per minute at \( t = 0 \) and as 975 counts per minute at \( t = 5 \) minutes. The decay constant is approximately:

A metallic sphere is placed in a uniform electric field. The line of force follow the path (s) shown in the figure as:

A machine gun has a mass 5 kg. It fires 50 gram bullets at the rate of 30 bullets per minute at a speed of 400 m/s. What force is required to keep the gun in position?

Electron in hydrogen atom first jumps from third excited state to second excited state and then from second excited to the first excited state. The ratio of the wavelength \( \lambda_1 : \lambda_2 \) emitted in the two cases is:

In a common emitter transistor amplifier \( \beta = 60 \), \( R_o = 5000 \, \Omega \) and internal resistance of a transistor is 500 \( \Omega \). The voltage amplification of amplifier will be:

The resistance of a wire is 'R' ohm. If it is melted and stretched to 'n' times its original length, its new resistance will be:

Which of the following is the correct lens formula?

A coil of 40 henry inductance is connected in series with a resistance of 8 ohm and the combination is joined to the terminals of a 2 volt battery. The time constant of the circuit is:

The magnetic field at a point due to a current carrying conductor is directly proportional to:

A body initially at rest and sliding along a frictionless track from a height h (as shown in the figure) just completes a vertical circle of diameter AB = D. The height h is equal to

Which one of the following statements is incorrect ?

A spring of force constant K is cut into two pieces such that one piece is double the length of the other.Then the long piece will have a force constant of