Q. Derive an expression for magnetic induction at a point on the equitorial line of a bar magnet.

Q. What is a Fermi energy level? What is its position in case of an intrinsic semiconductor?

Q. Which of the two meters, voltmeter or potentiometer, is preferred to measure the emf of a battery? Why?

Q. What is critical angle? Explain it with a neat ray diagram.

Q. State the laws of transverse vibrations in stretched strings. Give the procedures for verifying them using a sonometer.

Q. What is a thermal neutron? What is its importance?

Q. What is a photoelectric effect? Write any three laws of the photoelectric effect. Explain these laws by Einstein's equation of the photoelectric effect.

Q. Explain self-induction of a coil. Arrive at an expression for the induced emf in a coil and the rate of change of current in it.

Q. Explain neutral and inversion temperatures with the help of a graph between the thermo emf and the temperature of the hot junction in a thermocouple.

Q. Explain avalanche breakdown in a diode and zener breakdown in a zener diode.

Q. A current of $5$A is passing through a metallic wire of length $5$m and cross-sectional area of ${10}^{-5}{m}^2$. If the density of the electrons in the wire is $6.25\times {10}^{26}{m}^3$, find the time taken by the electrons to travel from one end of the wire to the other.

Q. A charge q of mass m starting from rest is allowed to move between two points having a potential difference of V volts. What is the final velocity of the charge?

Q. If a circular coil of $100$ turns and radius $10$cm carries a current of $1$A, find the magnetic dipole moment of the coil.

Q. Write about the main features in which the Fraunhofer and Fresnel approaches of diffraction differ.

Q. What is the capacity of a conductor? Explain the principle of a capacitor.

Q. What is radioactivity? Show that radioactive decay is exponential in nature. The half-life of a certain substance is $5$ days. How many days does this substance take for $31/{32}^{th}$ of the initial mass of disintegrate?

Q. Why is an eyepiece used in any optical instrument?

Q. What is deBroglie's hypothesis? Write the expression for the wavelength associated with a moving particle.

Q. What is the position of an object relative to the objective of a compound microscope? Where is its image formed?

Q. What is Curie temperature?

Q. What is the difference between amplitude modulation and frequency modulation?