JEE PHYSICS MCQ: CURRENT ELECTRICITY

1 Medium

1 of 1

Application +4 | -1

By what percentage will the illumination of the lamp decrease if the current drops by

20 \%

View answer and explanation

Correct option: C

36 \%

Option C (

36 \%

) is correct because the power is proportional to the square of the current, so a 20% drop in current results in a 36% decrease in power and illumination.

More Questions from CURRENT ELECTRICITY

Practice All Chapter MCQs →

The specific resistance of a wire is

\mathrm{\rho }

, its volume is

3\,\,{\mathrm{m}^3}

and its resistance is

3\,\,\mathrm{\Omega }

, then its length will be Magnitude of drift velocity per unit electric field is Statement-1: If a resistor is connected to a battery the current decreases when the temperature increases.
Statement-2: For most of the resistors, resistance increases with increase in temperature. The reciprocal of resistance is Corresponding to the resistance

4.7\,\, \times \,\,{10^6}\,\,\mathrm{\Omega }\,\, \pm \,\,5\,\,\%

, which is order of colour coding on carbon resistors? In a meter bridge, the gaps are closed by resistance 2 and 3 ohms. The value of shunt to be added to 3 ohm resistor to shift the balancing point by

22.5\,cm