An incandescent filament lamp rated 60 W, 230 V is connected to a household supply.
a. (i) Define electrical power in an electric circuit and state its SI unit.
b. (ii) If the potential difference across a resistor is doubled while its resistance remains constant, qualitatively explain why the rate of heat generation becomes four times.
c. (iii) The lamp specified above is accidentally connected to a 110 V supply of negligible internal resistance. Explain, without performing a detailed numerical calculation, why the lamp glows only dimly under this condition even though current still flows through its filament.