Two electric bulbs of same power, but with different marked voltage are connected in series across a power line. The brightness will be
- directly proportional to their marked voltages
- inversely proportional to their marked voltages
- directly proportional to their squares of marked voltages
- inversely proportional to their squares of their marked voltages
1 Answer
Correct option C
Explanation:
\(P=\frac{V^2}R=\frac{V'^2}{R'}\)
Higher watt means less resistance, when a number of bulbs are connected in series, a bulb with lower resistance will consume less power & the P.D (potential difference) across it will also be less. Therefore in series connection, a bulb with higher voltage will glow less brightly. Hence, their brightness will be proportional to the square of their marked voltage.
Topics from Physics
Physical Quantities
27
Electricity & Magnetism
48
Motion
8
Measurement
4
Electricity
166
Physical Optics
80
Waves
117
Force
51
Heat
137
Laws of Motion
1
Light
100
Pressure
139
Thermodynamics
1
Related Questions