Question

Two resistors of 8ohm and 12 ohm are connected in parallel. If the power dissipated in 8 ohm resistors is 9w what is power dissipated in 12 oh resistor

Answer 1

this is gonna be long
Data:
R1=8ohm
R2=12ohm
P1=9W
P2=?
So,
P=IV
V=IR
P=I²R
first we find the I (current) of R1
for R1
9=I²8
9/8=I²
1.125=I²
√1.125=I
I1=1.06 Ampere
so we can call this I1
current is distributed in a parallel circuit so current will be different while voltage would be same
Now lets find Voltage
V=I1R1
V=1.06*8
V=8.48
so this V is true for both R1 and R2
Lets find current of R2
V=I2R2
I2=R2/V
I2=12/8.48
I2=1.4Amperes
so far so good, lets find the power and get done with this
P2=VI2
P2=8.48*1.4
P2=11.8 watts

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