An electric bulb is rated 220 V and 100 W. When it is operated on 110 V, the power consumed will be ……………

1. 100 W
2. 75 W
3. 50 W
4. 25 W

Two conducting wires of the same material and of equal lengths and equal diameters are first connected in series and then parallel in a circuit across the same potential difference. The ratio of heat produced in series and parallel combinations would be

1. 1:2
2. 2:1
3. 1:4
4. 4:1

A copper wire has diameter 0.5 mm and resistivity of 1.6 × 10^–8 Ω m. What will be the length of this wire to make its resistance 10 Ω? How much does the resistance change if the diameter is doubled?

The values of current I flowing in a given resistor for the corresponding values of potential difference V across the resistor are given below –

Plot a graph between V and I and calculate the resistance of that resistor.