Q. Current in a circuit falls from $5.0A$ to $0.0A$ in $0.1sec$. If an average emf of $200V$ is induced, give an estimate of the self-inductance of the circuit.

Q. State and explain Coulomb's inverse square law in electricity.

Q. What is the Doppler effect? Obtain the expression for the apparent frequency of sound heard when the source is in motion with respect to an observer at rest.

Q. State and explain Biot-Savart Law.

Q. Explain how do you convert a moving coil galvanometer into an ammeter?

Q. Does the principle of conservation of energy hold for interference and diffraction phenomena? Explain briefly.

Q. What are the limitations of Bohr's theory of a hydrogen atom?

Q. What is the photoelectric effect?

Q. A bar magnet of length $0.1m$ and with a magnetic moment of $5{Am}^2$ is placed in a uniform magnetic field of intensity $0.4T$, with its axis making an angle of ${60}^o$ with the field. What is the torque on the magnet?

Q. Why are microwaves used in radars?

Q. State Kirchhoff's law for an electrical network. Using these laws, deduce the condition for balance in a Wheatstone bridge.

Q. A wire of resistance $4R$ is bent in the form of a circle. What is the effective resistance between the ends of the diameter?

Q. Why does the sun appear red during sunset and sunrise?

Q. Derive the expression for the capacitance of a parallel plate capacitor.

Q. State Heisenberg's uncertainty principle.