A 20.0- lamp and a 5.0- lamp are connected inseries and placed across a potential difference of 50.0-V. Whatis... a.) the equivalent resistance of the current? b.) the current in the circuit? c.) the voltage drop across each lamp? d.) the power dissipated in each lamp? A 20.0- lamp and a 5.0- lamp are connected inseries and placed across a potential difference of 50.0-V. Whatis... a.) the equivalent resistance of the current? b.) the current in the circuit? c.) the voltage drop across each lamp? d.) the power dissipated in each lamp?
Explanation / Answer
(a). equivalent resistance R = 20 ohm + 5 ohm =25 ohm (b). potential difference V = 50 V the current in the circuit i = V/ R = 2 A (c). voltage drop across 20 ohm lamp = 50 [ 20 / ( 20 + 5 )] = 40 Volt voltage drop across 5 ohm lamp = 50 [ 5 / ( 20 + 5 ) ] = 10 Volt (d). power dissipated P = Vi So, power dissipated in 20 ohm lamp = 40 * 2 = 80W power dissipated in 5 ohm lamp = 10 * 2 = 20 W