CBSE 12 Physics Question Paper-2024 Set-1

A thin plastic rod is bent in the form of a circular ring of radius R. It is uniformly charged with a charge density λ. The magnitude of the electric field at its centre is:

Ten capacitors, each of capacitance 1 μF, are connected in parallel to a 100 V source. The total energy stored in the system is:

Consider the circuit shown in the diagram. The potential difference between points A and B is:

A loop with a clockwise current I is located in the x-y plane, in a uniform magnetic field B along the z-axis. The loop will tend to:

A 10 cm long wire is placed along the y-axis. It carries a current of 1.0 A in the positive y-direction. A magnetic field B = (5 mT)j - (8 mT)k exists in this region. The force on this wire is:

The surface charge density of a charged sphere of radius r is σ. The electric field on its surface is E. If the radius of the sphere is doubled, while keeping the charge density same, the ratio of the electric fields of the old sphere and the new sphere will be:

A student is asked to connect four cells, each of emf E and internal resistance r, in series. However, he/she connects one of the cells incorrectly in series with the others. The equivalent emf and equivalent internal resistance of the combination will be, respectively:

A piece of wire is bent into a circular loop A and carries a current I. The wire is then bent into a circular loop B of two turns and carries the same current. The ratio of the magnetic fields at the centres of loop A and loop B will be:

Three charged small spheres X, Y and Z with charges +q, -q and +q respectively, are situated equidistant from each other as shown in the diagram. Spheres Y and Z are fixed in position. Initially X is also fixed at its place, but it is free to move. When X is released, the path traced by it will be:

In a uniform straight wire, the conduction electrons move along the +x direction. Let E and j be the electric field and current density in the wire respectively. Then:

Consider two concentric circular coils X and Y of radii R and r respectively, placed in the same plane. The coil Y is a galvanometer and a current I is flowing through the coil X. If the current in X is reversed, what is the induced charge flowing through the coil Y?

A light of wavelength 600 nm from a distant source falls on a slit of width 0.3 mm. The distance of the screen is 200 cm. The size of the central bright fringe is:

The peak voltage of an AC supply is 300 V. The rms voltage will be:

The electric potential at a point on the equatorial plane of an electric dipole is:

A rectangular wire loop of sides 8 cm and 2 cm with a small cut is moving out of a region of a uniform magnetic field of magnitude 0.3 T directed normal to the loop. The velocity of the loop is 1 cm s⁻¹ in the direction normal to the longer side. The emf developed across the cut is:

A proton and a deuteron, having the same momentum, enter a uniform magnetic field at right angles to the field. The ratio of the radii of their paths is:

An inductor of inductance 50 mH is connected to a resistor of resistance 10 Ω in series with a 5 V battery. The time constant of the circuit is:

An alternating emf is given by E = 140 sin(500t) V. If this is connected to a resistor of resistance 50 Ω, the rms current is:

A prism of a refracting angle 60° gives an angle of minimum deviation of 30°. The refractive index of the prism is:

A plane convex lens of focal length 20 cm is silvered at the plane surface. The focal length of the resulting mirror is:

If the electric flux coming out of a closed surface is zero, it signifies that:

In a series L-C-R circuit, the voltage across the resistance and inductance is 10 V and 20 V respectively. The voltage across the capacitance is also 20 V. The resonant frequency of the circuit is 100 Hz. The value of the resistance is:

An inductor of 20 mH, a capacitor of 100 μF and a resistor of 50 Ω are connected in series across an AC source of emf E = 10 sin(314t) V. The impedance of the circuit is:

A student measures the diameter of a wire using a screw gauge with least count 0.01 mm. The pitch of the screw gauge is 1.0 mm and there are 100 divisions on the circular scale. The diameter of the wire as measured is 2.13 mm. The number of circular scale divisions crossed by the main scale is 2 and the circular scale division coinciding with the main scale is 13. The zero error is:

If a coil of copper wire is immersed in a magnetic field, the induced emf produced in the coil is: