WORK SHEET 3 Current Electricity

 

 Current Electricity

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