Conservation and dissipation of energy

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Question 25
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An autonomous deep-sea research probe is equipped with a thermoelectric generator to harvest geothermal energy near a hydrothermal vent to power an acoustic beacon.

a.

Which equation links current (III), potential difference (VVV), and electrical power (PPP)?

  • Choice A: P=V×IP = V \times IP=V×I
  • Choice B: P=IVP = \frac{I}{V}P=VI​
  • Choice C: I=P×VI = P \times VI=P×V
  • Choice D: V=I2×PV = I^2 \times PV=I2×P
[1]
b.

When operating near the hydrothermal vent, the thermoelectric generator produces a potential difference of 24 V24\text{ V}24 V. The electrical power output of the generator is 14.4 W14.4\text{ W}14.4 W. Calculate the current generated by the thermoelectric generator.

[2]
c.

Which equation links efficiency, total power input, and useful power output?

  • Choice A: Efficiency=total power inputuseful power output\text{Efficiency} = \frac{\text{total power input}}{\text{useful power output}}Efficiency=useful power outputtotal power input​
  • Choice B: Efficiency=useful power output×total power input\text{Efficiency} = \text{useful power output} \times \text{total power input}Efficiency=useful power output×total power input
  • Choice C: Efficiency=useful power outputtotal power input\text{Efficiency} = \frac{\text{useful power output}}{\text{total power input}}Efficiency=total power inputuseful power output​
[1]
d.

The acoustic beacon has a total electrical power input of 6.5 W6.5\text{ W}6.5 W. The efficiency of the beacon in converting electrical power to acoustic signal power is 0.720.720.72. Calculate the useful acoustic power output of the beacon.

[2]

Conservation and dissipation of energy Questions

  1. GCSE
  2. /Physics
  3. /Conservation and dissipation of energy