Two lamps, one rated 100W ; 220V, and the other 60W ; 220V, are connected in parallel to electric mains supply. Find the current drawn by two bulbs from the line , if the supply voltage is 220V .
Answers
Answered by
9
P1=100 W , V = 220 V , P2= 60 W (GIVEN)
I1 = ? I2 = ?
P1= VI1
. : I1=P1/ V
= 100/220 = 0.46A
SIMILIARLY ,
I2=P2/ V = 60/220
= 0.27A
TOTAL CURRENT (I) = I1 + I2
= 0.46 + 0.27
I1 = ? I2 = ?
P1= VI1
. : I1=P1/ V
= 100/220 = 0.46A
SIMILIARLY ,
I2=P2/ V = 60/220
= 0.27A
TOTAL CURRENT (I) = I1 + I2
= 0.46 + 0.27
Answered by
1
Answer:
Power = P = 100 W
Voltage = V = 220v
Resistance = R
P = V²/R
100 = 220 ×220/R
R = 220 × 220/100
= 484 Ω
==========================
Power = P = 60 W
Voltage = V = 220v
Resistance = R
P = V²/R
60 = 220 × 220/R
R = 220× 220/60
= 806.7 Ω
=========================
As the resistors are connected in parallel ,
total resistance = 1/R
1/R = 1/484 + 1/806.7
= 806.7 + 484/484×806.7
= 1290.7/390442.8
R = 390442.8/ 1290.7 = 302.5 ohms
Total resistance = 302.5 Ω
I = current
V = IR
220 = I × 302.5
I = 220/302.5
= 0.73 A
The current drawn is 0.73 A
Explanation:
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