Unit 2 Physics January 2010

Please choose one of the following options for each question:

1. Identify which of the following pairs of units are both SI base units.

2. The resistance of a length of copper wire is 6 Ω. A second piece of copper wire has twice the length and twice the cross-sectional area. The resistance of the second piece of copper wire is

3. Which of the following statements about standing waves is not true?

4. A resistor is connected to a cell. An amount of charge Q passes through the resistor in a time t. During this time, the amount of chemical energy converted to electrical energy by the cell is E.

Select the row of the table which correctly gives the current in the resistor and the e.m.f. of the cell.

5. A cathode ray oscilloscope can be used to show how the displacement of a wave varies with time. Each square in the horizontal direction represents 5.00 ms.

The frequency of the wave is

6. The diagram shows the energy transfer for an electric motor.

The efficiency of the motor is

7. An electron is accelerated through a large potential difference and gains a kinetic energy of 47 keV. This energy expressed as joules equals

8. A source of sound moves away from an observer at a steadily increasing speed. Compared with the original sound, the wavelength reaching the observer will be

Use the diagram below for questions 9 and 10.

9. Which row in the table below correctly identifies the changes to the properties of the light as it enters the glass block?

10. The refractive index of the glass is