Current Electricity

  1. What is Ohm's law? Explain its significance in current electricity.
  2. State Kirchhoff's laws and explain their significance in current electricity.
  3. Define electric current and derive its expression in terms of drift velocity.
  4. Explain the concept of resistivity and its dependence on temperature for a conductor.
  5. Derive the expression for the resistance of a conductor in terms of its length, cross-sectional area, and resistivity.
  6. What is meant by the internal resistance of a cell? How does it affect the output voltage of a cell?
  7. State and explain Joule's law of heating.
  8. Describe the construction and working of a meter bridge. How is it used to measure the resistance of a conductor?
  9. Explain the principle of potentiometer and how it can be used to measure the emf of a cell.
  10. Define the term 'drift velocity' and explain how it is related to the applied electric field and relaxation time.
  11. Derive the expression for the drift velocity of electrons in a conductor in terms of the applied electric field, relaxation time, and the mass and charge of an electron.
  12. State and explain the phenomenon of superconductivity. How is it useful in practical applications?
  13. What is meant by the Hall effect? Explain how it can be used to determine the sign and density of charge carriers in a conductor.
  14. Define the term 'capacitance' and explain how it is related to the charge stored and the potential difference across a capacitor.
  15. Derive the expression for the capacitance of a parallel-plate capacitor in terms of its area, separation, and dielectric constant.