The resistance of a metal wire of length 1 m is 25 Ω at 20° C. If the diameter of the wire is 0.3 mm, What must be the resistivity of metal at that temperature?

Should the resistance of an ammeter be low or high? Give reason.

Why does the cord of an electric heater not glow while the heating element does?

Why are coils of electric toasters and electric irons made of an alloy rather than a pure metal ?

Two lamps, one rated 100 W at 220 V and the other 60 W at 220 V are connected in parallel to electron mains supply. What current is drawn from the line if the supply voltage is 220 V?