An observer is situated at the top of a tall tower. An aeroplane emitting sound at a frequency of 1000 Hz approaches the observer at a speed of 165 ms¯¹. The speed of sound is 330 ms¯¹. What is the frequency of the sound received by the observer?

What is the relationship between the amplitude of a wave and its intensity?

Which statement about light waves and sound waves is correct?

M and N are two electromagnetic waves. The ratio wavelength of M wavelength of N = 10⁵. What could M and N be?

A neutron decays to form a proton. Which particle is not involved in the decay process?

A nucleus of bismuth-212 (²¹²Bi) decays by the emission of an α-particle and γ-radiation.

Explain the main principles of the generation of ultrasound waves for medical use.