A filament lamp rated 40 W, 110 V is connected in series with a resistor R. If the supply voltage is 230 V, what should be the value of resistance R for the lamp to run at its rated voltage?

A room heater is rated 400 W, 220 V. If the supply voltage drops to 200 V, what will be the power consumed (approximately)?

A resistor is connected to a battery of 12 V emf and internal resistance 2 Ω. If the current in the circuit is 0.6 A, the terminal voltage of the battery is: