Phy 112 electromagnetism pass question paper

Phy 112 electromagnetism

1. What is the SI unit of electric charge?  

   a) Joule  

   b) Coulomb  

   c) Volt  

   d) Ampere  

2. The force between two point charges is inversely proportional to:  

   a) The square of the distance between them  

   b) The distance between them  

   c) The product of the charges  

   d) The sum of the charges  

3. The electric field inside a conductor in electrostatic equilibrium is:  

   a) Zero  

   b) Constant  

   c) Infinite  

   d) Dependent on the charge  

4. Which law describes the magnetic field due to a current-carrying wire?  

   a) Coulomb's law  

   b) Biot-Savart law  

   c) Faraday's law  

   d) Gauss's law  

5. The direction of the magnetic force on a moving charge is given by:  

   a) Right-hand rule  

   b) Left-hand rule  

   c) Fleming's right-hand rule  

   d) Ohm's law  

6. The unit of magnetic flux is:  

   a) Tesla  

   b) Weber  

   c) Henry  

   d) Gauss  

7. A transformer works on the principle of:  

   a) Electromagnetic induction  

   b) Coulomb's law  

   c) Ohm's law  

   d) Biot-Savart law  

8. The speed of electromagnetic waves in a vacuum is:  

   a) 3 × 10⁶ m/s  

   b) 3 × 10⁸ m/s  

   c) 3 × 10¹⁰ m/s  

   d) 3 × 10¹² m/s  

9. The energy stored in a capacitor is given by:  

   a) \( \frac{1}{2} CV^2 \)  

   b) \( \frac{1}{2} LI^2 \)  

   c) \( \frac{1}{2} QV \)  

   d) \( \frac{1}{2} IR^2 \)  

10. The Hall effect is used to measure:  

    a) Electric field  

    b) Magnetic field  

    c) Current  

    d) Resistance  

11. The SI unit of electric potential is __________.  

12. According to Coulomb's law, the force between two charges is directly proportional to the __________ of the charges.  

13. The electric field inside a hollow charged conductor is __________.  

14. The magnetic field lines around a straight current-carrying wire form __________ circles.  

15. The direction of the induced current is given by __________ law.  

16. The self-inductance of a solenoid depends on its __________ and the number of turns.  

17. The energy density of an electric field is given by __________.  

18. The displacement current is a concept introduced by __________.  

19. The Poynting vector represents the __________ of an electromagnetic wave.  

20. The skin depth of a conductor __________ with increasing frequency.  

21. The electric field inside a conductor is always zero. (True/False)  

22. Magnetic monopoles exist in nature. (True/False)  

23. The direction of the induced emf is always opposite to the change in magnetic flux. (True/False)  

24. The capacitance of a capacitor increases when a dielectric material is inserted. (True/False)  

25. The speed of light in a vacuum is the same for all electromagnetic waves. (True/False)  

66. The force between two parallel current-carrying wires is __________ if the currents are in the same direction.  

27. The magnetic field inside a long solenoid is __________.  

28. The unit of magnetic field strength is __________.  

29. The energy stored in an inductor is given by __________.  

30. The phenomenon of producing an emf by changing the magnetic flux is called __________.  

Essay Questions

1a. Explain the concept of polarization in dielectrics. How does it affect the capacitance of a capacitor?  

1b. Derive the expression for the magnetic field due to a long straight current-carrying wire using Ampère's circuital law.  

1c. What is the Hall effect? Derive the expression for the Hall voltage.  

2a. Explain the concept of eddy currents and give two practical applications.  

2b. Derive the expression for the energy density of an electric field.  

2c. State and explain Coulomb's law. Derive the expression for the force between two point charges.  

3a. Define electric flux and state Gauss's law. Use Gauss's law to derive the electric field due to an infinite plane sheet of charge.  

3b. Explain the concept of capacitance. Derive the expression for the capacitance of a parallel-plate capacitor.  

3c. What is an electric dipole? Derive the expression for the electric field at a point along the axial line of a dipole.  

4a. State and explain Faraday's law of electromagnetic induction. How does Lenz's law relate to Faraday's law?  

4b Derive the expression for the magnetic field at the center of a circular loop carrying current using the Biot-Savart law.  

4b. Explain the working principle of a transformer. Derive the relationship between the primary and secondary voltages and currents.  

5a. State all four Maxwell's equations in their integral form and explain their physical significance.  

5b Derive the wave equation for the electric field from Maxwell's equations.  

5c. Explain the concept of electromagnetic waves and describe the electromagnetic spectrum.