How is a voltmeter connected in the circuit to measure the potential difference between two points ?
The volt meter is always connected in parallel connection across the two points where the potential difference is to be measured in the circuit.
Explain the following:
(a) Why is the tungsten used almost exclusively for the filament of electric lamps?
(b) Why are the conductors of electric heating devices such as bread toasters and electric irons made of an alloy rather than a pure metal ?
(c) Why is the series arrangement not used for domestic circuits?
(d) How does the resistance of a wire vary with its area of cross-section?
(e) Why are copper and aluminium wires usually employed for electricity transmission?