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Class 12 Physics (India)

Course: Class 12 Physics (India) > Unit 3

Lesson 5: Cell, EMF, terminal voltage, & internal resistance
Science
Class 12 Physics (India)
Current electricity
Cell, EMF, terminal voltage, & internal resistance
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Cells: emf and internal resistance

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Problem

An external resistance, R, equals, 22, space, \Omega, is connected through a switch to a cell of emf, E, equals, 12, space, start text, V, end text, and internal resistance, r, equals, 2, point, 0, space, \Omega.
A voltmeter is connected across the cell.
What is the voltmeter reading when -
left parenthesis, start text, a, end text, right parenthesis the circuit is open (switch OFF)?
  • Your answer should be
  • an integer, like 6
  • a simplified proper fraction, like 3, slash, 5
  • a simplified improper fraction, like 7, slash, 4
  • a mixed number, like 1, space, 3, slash, 4
  • an exact decimal, like 0, point, 75
  • a multiple of pi, like 12, space, start text, p, i, end text or 2, slash, 3, space, start text, p, i, end text
start text, V, end text
left parenthesis, start text, b, end text, right parenthesis the circuit is closed (switch ON)?
  • Your answer should be
  • an integer, like 6
  • a simplified proper fraction, like 3, slash, 5
  • a simplified improper fraction, like 7, slash, 4
  • a mixed number, like 1, space, 3, slash, 4
  • an exact decimal, like 0, point, 75
  • a multiple of pi, like 12, space, start text, p, i, end text or 2, slash, 3, space, start text, p, i, end text
start text, V, end text
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