Unit 2 Physics January 2012

Please choose one of the following options for each question:

1. Which of the following electromagnetic radiations has the lowest frequency?





2. When light from a distant star reaches us on Earth, its wavelength appears shifted towards the red end of the spectrum. This is because





Two loudspeakers produce identical sounds of frequency 440 Hz which superpose to produce a standing wave. Adjacent nodes are formed 0.75 m apart.
Select the correct statement about the waves





4. The diagram shows an experiment set up to demonstrate two-source interference, using microwaves of wavelength Ȝ.

The detector is moved from O in the direction of the upwards arrow. The first position where the signal is a minimum is P.
The equation that correctly determines the position of P is





5. During a thunderstorm, a flash of lightning resulted in 600000 C of charge flowing in a lightning conductor in a time of 40 ms. The current in the conductor was





6. The unit of potential difference can be expressed as





7. A steady potential difference is applied across a variable resistor that is kept at a constant temperature.

The graph which represents the relationship between the resistance R of the variable resistor and the current I through it is





8. Early experiments to measure the speed of light involved timing pulses of light being reflected back from distant mirrors. If a pulse of light was emitted and then detected 0.24 ms later, the distance to the mirror was





9. The diagram represents straight wavefronts passing across a boundary from deep water into shallow water, with a change in speed and direction.

Which wave property does this diagram illustrate?





10. Which of the following quantities is shown with the correct unit?






u