Q15 of 126 Page 196

Would you prefer a voltmeter or a potentiometer to measure the emf of a battery?

A Potentiometer will be preferred to measure the emf of a battery as it uses the null pointer method, hence draws very little to no current from the circuit, and hence gives an accurate measure of the emf. In a voltmeter the equivalent resistance of the circuit changes and hence the potential difference to be measured changes. To minimize this change the voltmeter resistance needs to be very high.


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Sometimes it is said that “heat is developed” in a resistance when there is an electric current in it. Recall that heat is defined as the energy being transferred due to the temperature difference. Is the statement under quotes technically correct?

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We often say “a current is going through the wire”. What goes through the wire, the charge or the current?

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Does a conductor become charged when a current is passed through it?

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