photo.jpg

# Kalyani's Physics Flashback ## Previous Year Questions with Answers ### 2002 1. The potential difference across a cell of emf 4V drops to 2V when a current of 2A is drawn from it. What is the internal resistance of the cell? 2. Potential difference across two wires of different materials but of...

# Kalyani's Physics Flashback ## Previous Year Questions with Answers ### 2002 1. The potential difference across a cell of emf 4V drops to 2V when a current of 2A is drawn from it. What is the internal resistance of the cell? 2. Potential difference across two wires of different materials but of same length and same radius is maintained constant. How is the heat produced in the wires related to the specific resistance ρ at each wire? 3.  4. What is the value of I in the given circuit? 5. What is meant by drift velocity? State the equation relating the electric current and drift velocity. 6. A metal of specific resistance 64×10-6 Ωcm and length 2m has a resistance of 20Ω. Calculate its radius. 7. Explain why manganin is used as resistance coil in resistance boxes instead of copper? 8. A 200watt electric bulb is connected to a 220 volt mains, Find the resistance of the filament. 9. State and explain Kirchhoff's laws in electricity. Apply them to the case of a balanced Wheatstone's bridge. 10. Explain drift velocity. Derive an expression for current in terms of drift velocity. Derive a relation between current density and electric field. ### 2003 11. You are given 20cells each of emf 1.5volt and internal resistance of 0.3 ohm. How would you arrange them to produce the maximum current in a circuit of 1.5 ohm resistance?