## Sunday, May 17, 2009

### CURRENT ELECTRICITY TEST Q.NO-4

CURRENT ELECTRICITY TEST Q.NO-4

3-MARKS
1.Difference between electric energy and electric power?
2.Define temperature coefficient of resistance?
3.Define tolerance.Give example.
4.What are the changes observed at transition temperature?
5.Draw the circuit for wheatstone bridge?
6.Define current density?
7.What are carbon resistors.what are colour codes for carbon resistors?
8.The effective resistance are 10ohm,2.4ohm.when two resistors are connected in series and parallel what are the resistances of individual resistors?
9.Define resistivity of a material
10.How are material classified based on resistivity?
11. Why is copper wire not suitable for a potentiometer?
12.The colour of a carbon resistors is orange,orange,orange what is the value of resister?
13.Explain the flow of charges in a metallic conductor?
14.10ohm resistance is connected in series with cell of emf 10V.A voltmeter is connected in parallel to a cell and it reads 9.9V.find internal resistance of cell?
15.An incandescent lamp is operated at 240V and the current is 0.5A what is the resistance of the lamp.
5 MARK

1. Explain and verification of faradays law of electrolysis?
2. Explain about superconductivity?
3. Find the current flowing across three resistor 3ohm,5ohm and 2ohm connected in parallel to 15V supply.Also find the effective resistance and total current drawn from the supply?
4. The resistance of a platinum wire at 0 degree Celsius is 4V.what will be the resistance of the wire at 100degree celsius. If the temperature coefficient of resistance of platinum is 0.0038/degree celsius.
5. How can emf of two cells be compared using potentiometer?
6. Explain Wheatstonebridge and derive expression for bridge balance.
7. Find expression for effective resistance of resistor connected in parallel?