Minor focus exam Q's

Question 1

Many hydroelectric power schemes use a technique

known as pumped storage. Explain what is meant by pumped storage.

Answer 1

When the demand for electricity is low, excess (‘leftover’) electrical
energy which has been generated elsewhere [1] is used to pump water
back into the reservoir (‘lake’) above a hydroelectric power station [1].
This water can be released back through the turbines as an when extra
electrical energy is required elsewhere [1].

Question 2

Type of
radiation: Alpha
Description:  Helium nucleus 
Typical range: in air 5 – 10 cm
Stopped by: Paper

Gamma Electromagnetic
radiation Very long Thick sheet of
lead/concrete

Answer 2

Type of radiation: Beta Fast-moving
electron
10 cm –
several metres
Thin sheet of
aluminium