List of top Physics Questions

A running man has half the kinetic energy of that of a boy of half his mass. The man speeds up by 1m/s so as to have same K.E. as that of the boy. The original speed of the man will be:

A steel wire of length \( \ell \) has a magnetic moment \( M \). It is then bent into a semicircular arc. The new magnetic moment is:

Four point charges \( -Q, -2Q, 2q \) and \( 4q \) are placed, one at each corner of the square. The relation between \( Q \) and \( q \) for which the potential at the centre of the square is zero is:

In the circuit shown the cells A and B have negligible resistances. For \( V_A = 12 \, \text{V} \), \( R_1 = 500 \, \Omega \) and \( R = 1000 \, \Omega \), the galvanometer \( G \) shows no deflection. The value of \( V_B \) is:

In the given circuit the reading of voltmeter \( V_1 \) and \( V_2 \) are 300 volt each. The reading of the voltmeter \( V_3 \) and ammeter \( A \) are respectively:

The Binding energy per nucleon of \( \dfrac{3}{2} Li \) and \( \dfrac{4}{2} He \) nuclei is 5.60 MeV and 7.06 MeV, respectively.

A ray PQ incident on the refracting face BC is refracted in the prism BA as shown in the figure and emerges from the other refracting face AC as RS such that \( \angle AQ = \angle RS \). If the angle of prism \( A = 60^\circ \) and the refractive index of the material of prism is \( \sqrt{3} \), then the angle of deviation of the ray is:

In a photoelectric effect measurement, the stopping potential for a given metal is found to be \( V_0 \) volt when radiation of wavelength \( \lambda_0 \) is used. If radiation of wavelength \( 2\lambda_0 \) is used with the same metal then the stopping potential (in volt) will be:

The ratio of radii of the first three Bohr orbits is:

A large number of liquid drops each of radius \( r \) coalesce to form a single drop of radius \( R \). The energy released in the process is converted into kinetic energy of the big drop \( M \) is given by (given, surface tension of liquid \( \sigma \)):

Find the magnetic field at \( P \) due to the arrangement shown:

The given electrical network is equivalent to:

The principle of conservation of linear momentum can be strictly applied during a collision between two particles provided the time of impact:

An alternating voltage of 220 V, 50 Hz frequency is applied across a capacitor of capacitance 2 μF. The impedance of the circuit is:

The length of elastic string, obeying Hooke’s law, is \( \ell_1 \) metres when the tension 4N and \( \ell_2 \) metres when the tension is 5N. The length in metres when the tension is 9N is:

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:

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

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

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: