PHYSICS IMPORTANT QUESTIONS

PHYSICS IMPORTANT QUESTION ANSWERS

BY AARISH SIR

2-Mark Important Questions

1. Write the characteristics of equipotential surfaces.

2. Why does the capacitance increase when a dielectric medium is placed between the plates of a capacitor?

3. When we start a car, why do its headlights dim for a while?

4. Write Ohm’s Law.

5. Write Kirchhoff’s rules for electrical circuits.

6. Write any two differences between Ammeter and Voltmeter.

7. Write Coulomb’s Law.

8. On the basis of Ohm’s Law, define resistance and give its unit.

9. How can the sensitivity of a moving coil galvanometer be increased?

10. What are magnetic field lines? Write their properties.

11. Write two examples each of diamagnetic, paramagnetic, and ferromagnetic materials.

12. Write Faraday’s Laws of Electromagnetic Induction.

13. Write any two differences between self-induction and mutual induction.

14. Write Fleming’s Right-Hand Rule.

15. What is sky polarization?

16. Write Ampere’s Circuital Law.

17. What is a transformer?

18. Why do two like charges repel each other?

19. What is total internal reflection? Write the necessary condition for it.

20. What is the angle of polarization?

21. What is interference? Give one example.

22. Explain the principle of superposition of light waves.

23. What do you mean by coherent source?

24. State clearly the conditions for obtaining bright and dark fringes.

25. What is the difference between light waves and sound waves?

26. What is heat radiation? Name the substance which has maximum emissive power.

27. Explain Huygens’ principle.

28. What is the Balmer series in the hydrogen spectrum?

3-Mark Important Questions

1. Prove that the potential at any point on the perpendicular bisector of an electric dipole is zero.

2. Derive the expression for equivalent capacitance in parallel and series combinations and draw their circuit diagrams.

3. State Kirchhoff’s Laws and explain them.

4. Draw the circuit diagram of a Wheatstone bridge. Explain its principle and derive the condition for balance ( P/Q = R/S ).

5. Establish a relation between internal resistance, terminal voltage, and current of a cell.

6. Establish the relation between drift velocity of electrons and current.

7. Differentiate between resistance and resistivity.

8. State Lenz’s Law of electromagnetic induction and explain how it is consistent with the law of conservation of energy.

9. Explain the principle of hydrogen’s second spectral line (Balmer series).

10. What is interference? Write its conditions.

11. Differentiate between interference and diffraction.

4-Mark Important Questions

1. State and prove Gauss’s Law related to electric flux.

2. What is an electric dipole? Derive the expression for the electric field intensity at a point due to an electric dipole in the axial position.

3. Write any four differences between self-induction and mutual induction.

4. What is a dynamo? Explain the principle and construction of an AC dynamo with a labeled diagram.

5. Explain transformer under the following points:

   1. Labeled diagram

   2. Principle

   3. Formula for transformation ratio

   4. Causes of energy loss and methods to reduce them

6. For an AC circuit containing L, C, and R, draw a phasor diagram, derive the expression for impedance, and establish the relation between current and electromotive force at each instant.

7. Describe the simple microscope under the following headings:

   1. Ray diagram of image formation

   2. Expression for magnifying power when the final image is formed —
      (a) at the least distance of distinct vision,
      (b) at infinity.

8. Derive the mirror formula for a spherical mirror.