Magnetic fields (A-level only)

Medium

A geothermal exploration probe uses two different resistive heating systems to maintain its internal temperature:

System 1: A steady direct current $I$ is passed through a heating element of resistance $R$ , dissipating a power $P$ .
System 2: An alternating current with a peak value of $3 I$ is passed through a secondary heating element of resistance $0.4 R$ .

What is the average power dissipated by the secondary heating element in System 2?

$0.6 P$

$1.2 P$

$1.8 P$

$3.6 P$

Magnetic fields (A-level only) Questions