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A level: Radioactivity Questions

Q19. A Radioisotope Thermonuclear Generator (RTG) is a device that uses some of the energy from radioactive decay to generate electricity.

The Mars rover Curiosity includes an RTG that contains plutonium-238.

The plutonium undergoes alpha decay and some of the energy is used to generate about 100 W of electrical power.

(a) Complete the equation for the alpha decay of plutonium-238.

[2 marks]

(b) Only 6% of the energy from the decay is used to generate electricity.

Calculate the rate at which energy is transferred from the decay of plutonium-238 on Curiosity.

[1 mark]

(c) The RTG has a constant output voltage of 32 V.

Calculate the current when the output power is 100 W.

[1 mark]

(d) Calculate the maximum number of components, each of resistance 45 Ω, that can be connected in parallel across the RTG before the maximum output power is reached.

[2 marks]

(e) The alternative to using an RTG is to use a solar panel.

A typical solar panel installation on a house roof in the UK provides about 1000 kW h of electricity each year.

Calculate the average electrical power output of the installation.

[2 marks]

(Total 8 marks)