Unit 2 Physics January 2013

Please choose one of the following options for each question:

1. An ampere can be expressed as

2. Which of the following summarises the change in wave characteristics when going from ultraviolet to infrared in the electromagnetic spectrum?

3. Electrical power is transferred in a motor as shown.

What is the efficiency of the motor?

4. A ray of monochromatic light passes into a glass block as shown.

The refractive index of the glass for this light is

5. An electron is accelerated from rest through a potential difference of 5.0 kV.

The kinetic energy gained by the electron is

6. A particular sound is investigated by connecting a microphone to an oscilloscope. The diagram shows the trace of a sound wave on the oscilloscope. The screen of the oscilloscope has a grid on it. On the x-axis 1 division represents 5 ms.

The frequency of the sound wave is

7. Two coherent sources emit waves of wavelength λ which are in phase. The two points meet at a point, having travelled slightly different distances. The waves now have a phase difference of 180°.

Which of the following could be the path difference at this point?

8. The potential difference between points A and B is

9. Ultrasound is used to investigate the blood in an artery in a human body by detecting a Doppler shift. This Doppler shift is used to measure the

10. The effect of diffraction is more noticeable, in everyday life, with sound than with light. This is because