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- PHY102 Physics II © Dr.Cem Özdoğan
- 27-3 Work, Energy and emf
- Consider a circuit consisting of a battery as emf source and resistor of resistance R;
- Emf ,ξ, of the device is shown by arrow (starting from – to + terminal)
- In any time interval dt, a charge dq passes through any cross section of the circuit shown, such as aa’.
- This same amount of charge must enter the emf device at its low-potential end and leave at its high-potential end.
- Emf device must do an amount of work dW on the charge dq to force it to move in this way.
- We define the emf of the emf device in terms of this work:
- An ideal emf device is one that has no internal resistance to the internal movement of charge from terminal to terminal.
- The potential difference between the terminals of an ideal emf device is exactly equal to the emf of the device.