Worksheets on Electricity

Electricity Worksheet-19

1. An electric bulb draws 1.2 A current at 6.0 V. Find the resistance of the bulb.

2. Which will have a higher resistivity: a conductor or an insulator ?

3. Two wires of same material and same length have radii r¹ and r² respectively. Compare their resistances.

4. Name a substance whose resistance decreases with temperature.

5. Name a substance whose resistance almost remains unchanged by increase of temperature.

6. Distinguish between kilowatt and kilowatt hour.

Electricity Worksheet-20

1. Two wires are of the same material but of different lengths and areas of cross-section. Will their resistivity be same or different ?

2. Why is nichrome used as a heating element ?

3. What is the difference between a resistor and resistance ?

4. Why are constantan and manganin used for making standard resistances ?

5. Why is lead-tin alloy used for making fuse ?

6. Why are copper and aluminium wires used as transmission lines for electric power ?

Electricity Worksheet-21

1. A given wire is stretched to double its length. How will its resistance change ?

2. A wire of 3 Ω a resistance and 10 cm length is stretched to 30 cm length. Assuming that it has uniform cross-section, what will be its new resistance ?

3. A rheostat and a resistance box are both used to change current in a circuit. In what respect the two differ from each other?

4. How do we symbolically represent a connecting wire and a resistor ? What is the significance of the symbol of a resistor ?

5. What sets the electrons into motion in an electric circuit ?