Physics (AS & A Level) · Oct / Nov 2019 · Paper 13 · Question 26

In an experiment to demonstrate a stationary wave, two microwave transmitters, emitting waves of wavelength 4 cm, are set facing each other, as shown. [diagram: two transmitters facing each other with a detector at distance d from the left-hand transmitter] A detector is moved along a straight line between the transmitters. It detects positions of maximum and minimum signal. The detector is a distance d from the left-hand transmitter. Assume that both transmitters are at antinodes of the stationary wave. Which row gives a value of d for a maximum and for a minimum?

1. Avalue of d for a maximum / cm: 46; value of d for a minimum / cm: 48
2. Bvalue of d for a maximum / cm: 47; value of d for a minimum / cm: 48
3. Cvalue of d for a maximum / cm: 48; value of d for a minimum / cm: 47
4. Dvalue of d for a maximum / cm: 49; value of d for a minimum / cm: 47

As printed in the paper