HSC Science Class 12 - Tamil Nadu Board of Secondary Education Question Bank Solutions

Derive the expression for resultant capacitance, when the capacitor is connected in series.

Derive the expression for resultant capacitance, when the capacitor is connected in parallel.

Calculate the resultant capacitances for each of the following combinations of capacitors.

During a thunder storm, the movement of water molecules within the clouds creates friction, partially causing the bottom part of the clouds to become negatively charged. This implies that the bottom of the cloud and the ground act as a parallel plate capacitor. If the electric field between the cloud and ground exceeds the dielectric breakdown of the air (3 × 10⁶ Vm^–1), lightning will occur.

1. If the bottom part of the cloud is 1000 m above the ground, determine the electric potential difference that exists between the cloud and ground.
2. In a typical lightning phenomenon, around 25 C of electrons are transferred from cloud to ground. How much electrostatic potential energy is transferred to the ground?

For the given capacitor configuration

1. Find the charges on each capacitor
2. potential difference across them
3. energy stored in each capacitor.

Capacitors P and Q have identical cross-sectional areas A and separation d. The space between the capacitors is filled with a dielectric of dielectric constant Er as shown in the figure. Calculate the capacitance of capacitors P and Q.

What is magnetic permeability?

State Ampere’s circuital law.

Define ampere.

Find the magnetic field due to a long straight conductor using Ampere’s circuital law.

Calculate the magnetic field inside and outside of the long solenoid using Ampere’s circuital law

What are LC oscillations?

Explain the generation of LC oscillations in a circuit containing an inductor of inductance L and a capacitor of capacitance C.

Show that the total energy is conserved during LC oscillations.

Prove that energy is conserved during electromagnetic induction.

In a series LC circuit, the voltages across L and C are 180° out of phase. Is it correct? Explain.

Two point white dots are 1 mm apart on a black paper. They are viewed by eye of pupil diameter 3 mm approximately. The maximum distance at which these dots can be resolved by the eye is, [take wavelength of light, λ = 500 nm]

State the laws of reflection.

State the law of refraction.

Prove laws of reflection using Huygens’ principle.