Quiz

To sum up everything that you have learnt in this website, I implore you to take some of the questions that I've handpicked. These questions will help you to remember better about the information on this website, and also, as the chinese proverb says,

“熟能生巧”.

Practice Makes perfect.

1.What happens when an ebonite rod is rubbed with a duster?

2.An electrostatiscally charged object will pick up small pieces of paper. Which of the following will not pick up pieces of paper? (a)an eathed metal rod rubbed with a duster (b)a plastic comb pulled through dry hair (c)a polyethene rod rubbed with a woolen cloth (d)a rubber balloon rubbed on a nylon shirt

3.The total energy dissipated in a circuit when a charge of 5.0 C flows from the battery is 20 J. What is the e.m.f of the battery?

4.What describes the electromotive force of a cell?

5.A wire of cross-sectional area A and length L has a resistance of R. Which of the following wire has a resistance of R/2? (a)A wire that has a cross-sectional area of 2A and a length of L/2 (b)A wire that has a cross-sectional area of A and a length of 2L (c)Cross-sectional area of 2A and a length of L (d)has a cross-sectional area of 2A and a length of 2L

6.A generator produces 100kW of power at a potential difference of 10kV. The power is transmitted through cables of total resistance 5 ohms. how much power is dissipated in the cables?

7.The amount of energy transferred when 10C of charge passes through a p.d. of 10V is the same as the energy needed to raise a 2kg mass through a distance x. [gravitational field strenght=10N/kg]. what is the value of x?

8.A flashlight bulb is connected to a 3 V battery of negligible internal resistance. The ammeter shows a reading of 0.70 A. What is the electrical power used by the bulb?

9.A hot water heater is rated 2880W,240V.Calculate the operating current.

10. How is the flemming's left hand rule used?

(answers below)

Answer key 1. The rod becomes negatively charged as the duster has lost some electrons to the rod 2.(a) 3. 4.0 V 4. The total energy used to drive unit charge round the complet circuit 5.(c) 6.500W 7. 10m 8. 2.1W 9. 12A 10. It gives the direction of the motion of the wire coil when it is placed in a magnetic field