Power Management

What is the difference between power and energy?

  1. APower and energy are the same thing with the same unit
  2. BEnergy is a unit of voltage and power a unit of current
  3. CPower is energy used per unit time (W), and energy is power accumulated over time (J)
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Answer: C. Power is energy used per unit time (W), and energy is power accumulated over time (J)

Power (watts) is the rate of use at a given moment and matters for heat and supply design. Energy (joules) is power times time and matters for battery life and electricity bills. Halving power while doubling time leaves energy unchanged. When considering power-saving measures, it is important to distinguish whether the issue is temperature (power) or battery life (energy).

  • A. They are different quantities.
  • B. Voltage is in V, current in A.
  • C. Correct. Running at 1 W for 1 second uses 1 J.
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More Power Management questions

  1. Which metric is most suitable for comparing processor energy efficiency?
  2. In today's chips, which statement comparing the energy of moving data and computing is generally correct?
  3. Among DRAM power-saving states, which describes self-refresh?
  4. DRAM operated at high temperature may require shorter refresh intervals. Which pairs the reason with the effect on power correctly?
  5. To cut power on a microcontroller, what should be done with unused peripherals such as timers and UARTs?