Question

Can anyone help me on question 13

Answer 1

Given that in a parallel circuit:

R1 = 12 ohms

R2= 15 ohms

I = 12 A

I2 = 4 A

V=?

R=?

R3 =?

P=?

Since,

V= IR

or,

V2 = I2 * R2

V2= 4* 15

V2 = 60V

Since in a parallel circuit voltage remain same in all component of the circuit and is equal to the source voltage.

Therefore,

V= V1 = V2 = V3 = 60V

Since,

V= IR

R= V/I

R= 60/12

R= 5 ohm

That is total resistance is equal to 5 ohms.

Since for parallel circuit,

1/R= 1/R1 + 1/R2 + 1/R3

1/5= 1/12+ 1/15 + 1/R3

or

1/R3= 1/5- 1/12- 1/15

1/R3= 1/20

or

R3= 20 ohms

Since,

V=IR

I= V/R

I1= V1/ R1

I1= 60/12

I1= 5 A

I3= V3/R3

I3= 60/20

I3= 3A

Since,

P=VI

P= 60*12

P=  720 watt

P1= V1* I1

P1= 60* 5

P1= 300 watt

P2= V2* I2

P2= 60* 4

P2= 240watt

P3= V3*I3

P3= 60*3

P3= 180 watt

Hence we have,

R1= 12 ohms , R2= 15 ohms, R3= 20 ohms, R= 5 ohms

I1= 5A, I2= 4A, I3= 3A, I= 12 A

V1= V2= V3= V= 60V

P1= 300 watt, P2= 240 watt, P3 = 180 watt, P= 720 watt