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Course: Class 10 Physics (India) > Unit 3

Lesson 7: Electric power and heating effect of current
Science
Class 10 Physics (India)
Electricity
Electric power and heating effect of current
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Electric power (formula)

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Problem

Diane is building her own electronic calculator.
She maintains a potential difference, V=3.0 mV, in one of its circuits with power, P=21 mW.
What is the amount of charge, Q, that moves through the circuit during a time period, t=10 s?
Note: Let's calculate in the SI unit.
Q=
  • Your answer should be
  • an integer, like 6
  • a simplified proper fraction, like 3/5
  • a simplified improper fraction, like 7/4
  • a mixed number, like 1 3/4
  • an exact decimal, like 0.75
  • a multiple of pi, like 12 pi or 2/3 pi
C