## 13 April 2014

### CBSE Physics Numerical based on chapter - Electricity & its effects For (Class X)

NUMERICAL - Electricity and its effects For (Class X)
1. A resistance of 6 ohms is connected in series with another resistance of 4 ohms. A potential difference of 20 volts is applied across the combination. Calculate the current through the circuit and potential difference across the 6 ohm resistance.

2. Calculate the number of electrons constituting one coulomb of charge per second through any cross section of a conductor.

3. How much work is done in moving a charge of 2 C across two points having a potential difference of 12 V ?

4. How much energy is given to each coulomb of charge passing through a 6 V battery ?

5. Calculate the work done in moving a charge of 5 Coulombs from a point at a potential of 210 Volts to another point at 240 Volts.

7. When a particle of charge 10 µC is brought from infinity to a point P, 2.0 mJ work is done by the external forces. What is the potential at P ?

9. How many electrons pass through a lamp in one minute if the current be 200 mA?

10. Calculate the current supplied by a cell if the amount of charge passing through the cell in 4 seconds is 12 C ?

11. A 2 Volt cell is connected to a 1 Ω resistor. How many electrons come out of the negative terminal of the cell in 2 minutes?

12. a) How much current will an electric bulb draw from a 220 V source, if the resistance of the bulb filament is 1200 Ω ?

b) How much current will an electric heater coil draw from a 220 V source, if the resistance of the heater coil is 100 Ω ?

13. The potential difference between the terminals of an electric heater is 60 Volts when it draws a current of 4 Ampere from a source. What current will the heater draw if the potential difference is increased to 120 Volt.

14. A torch bulb when cold has 1Ω resistance. It draws a current of 0.3 Ampere when glowing from a source of 3 V. Calculate the resistance of the bulb when glowing and explain the reason for the difference in resistance.

15. A current of 0.2 Ampere flows through a conductor of resistance 4.5 Ω. Calculate the potential difference at the ends of the conductor.