Question

Define electric power. Express it in terms of potential difference (V) and resistance (R).

An electric oven is designed to work on the mains voltage of 220 V. This oven consumes 11 units of electrical energy in 5 hours. Calculate : (a) power rating of the oven (b) current drawn by the oven (c) resistance of the oven when it is red hot

State whether the currents and potential difference in all the bulbs will be same or different when in a circuit three bulbs of : (a) same wattage are connected in series. (b) same wattage are connected in parallel. (c) different wattage are connected in series. (d) different wattage are connected in parallel.

Two identical resistors of 24 Ω each are connected to a battery of 6 V. Calculate the ratio of the power consumed by the resulting combinations with (a) minimum resistance and (b) maximum resistance.

Draw a schematic diagram of a circuit consisting of a battery of six 2V cells, a 6 Ω resistor, a 12 Ω resistor and a 18 Ω resistor and a plug key all connected in series. Calculate the following (when key is closed) : (i) Electric current flowing in the circuit. (ii) Potential difference across 18 Ω resistor. (iii) Electric power consumed in 18 Ω resistor.