Unit 2 Physics January 2011

Please choose one of the following options for each question:

1. The amount of electrical energy transferred when a charge of 8 mC moves through a potential difference of 12 V is

2. The battery in the circuit has negligible internal resistance and an e.m.f. of 12 V.

The potential difference across the parallel combination is

3. A stationary observer hears a sound emitted by a moving source .
This produces a Doppler effect which is a

4. The diagram shows four electron energy levels in an atom. The transition of an electron from level 3 to level 1 is shown. This results in the emission of a photon in the visible range.

Which transition might emit a photon in the ultraviolet range?

5. In the circuit shown, the battery has negligible internal resistance. L, M and N are identical lamps.

The filament of lamp M breaks. Identify the row of the table which shows the resulting changes in the brightness of lamps L and N.

6. Which of the following can be used as a unit of electrical resistance?

7. Two waves have the same frequency and are travelling in the same medium.
The two waves can produce a standing wave if they

8. The drift velocity v of electrons in a conductor is directly proportional to

9. In the 1930s, experiments were performed where beams of X-rays or beams of high energy electrons were directed through a crystal as shown in the diagram.

Which of the following statements about the experiments is correct?

10. The graph shows how the current I varies with potential difference V for an electrical component.

Which row of the table gives the resistance of the component at V2 and describes how the resistance changes from V1 to V2?