Two lamps, one rated at 40W - 220 volt and the other at 60 W, - 220 volt are connected in parallel to the electric supply at 220 volt. (a) Draw a circuit diagram to show the connections. (b) Calculate the current drawn from the electric supply source. (c) Calculate the total energy consumed by the two lamps together when they operate for one hour.
Answers
Answer:
Given,
Power of 1st lamp, P1 = 40W, Voltage of 1st lamp, V1 = 220V
Power of 2nd lamp, P2 = 60W, Voltage of 2nd lamp, V2 = 220V
(a) Circuit diagram of the connections.
(b) Voltage across both the lamps is the same and equal to 220V.
We know that,
P=V×I, where P = Power, V = Voltage, I = Current.
In term of Current I, it can be given as-
I=PV
Now,
Current through 40W lamp = I1 =
P1V =
40220A
Current through 60W lamp = I2 =
P2V =
60220A
Total current drawn from the electric supply =
40220+60220=0.45A
(c) Energy consumed by 40W lamp in 1hr, E1=P1×t=40×1=40Wh
So, energy consumed by Lamp-1 = 40×3.6=144kJ [∵1Wh=3.6kJ]
Energy consumed by 60W lamp in 1hr, E2=P2×t=60×1=60Wh
So, energy consumed by Lamp-2 = 60×3.6=216kJ [∵1Wh=3.6kJ]
Total energy consumed = (Energy consumed by Lamp-1 + Energy consumed by Lamp-2) = 144 + 216 = 360kJ
Hence, the total energy consumed by the two lamps together when they operate for one hour is 360kJ.
Answer:
40220A
Current through 60W lamp = 12 =
P2V =
544
60220A
Total current drawn from the electric supply =
40220+60220=0.45A
(c) Energy consumed by 40W lamp in 1hr, E1 P1xt=40x1=40Wh
So, energy consumed by Lamp-1 =
40x3.6 144kJ [:*1Wh=3.6kJ]
Energy consumed by 60W lamp in 1hr, E2=P2xt=60×1=60Wh
So, energy consumed by Lamp-2 = 60x3.6-216kJ [1Wh=3.6kJ]
Total energy consumed = (Energy consumed by Lamp-1 + Energy consumed by Lamp-2) = 144 +216 360kJ
Hence, the total energy consumed by the two lamps together when they operate for