Question

Question 43:
Show with the help of diagrams, how you would connect three resistors each of resistance 6 Ω, so that the combination has resistance of (i) 9 Ω (ii) 4 Ω.

Lakhmir Singh Physics Class 10

Answer 1

Answer:

R1 and R2 are in series and RS and R3 are in parallel

Answer 2

Answer:

(i) To obtain equivalent resistance of 9Ω, two resistors of 6Ω should be in parallel combination and then the parallel combination should be connected to another 6Ω resistor in series combination.

R1 = 6Ω

R2 = 6Ω

R3 = 6Ω

1/R' = 1/R1 + 1/R2

1/R' = ( 1/6 + 1/6 )Ω

1/R' = 1/3Ω

R' = 3Ω

R = R' + R3

R = (3 + 6)Ω

R = 9Ω

(ii) To obtain equivalent resistance of 4Ω, two resistors of 6Ω should be in series combination and then the series combination should be connected to another 6Ω resistor in parallel combination.

R1 = 6Ω

R2 = 6Ω

R3 = 6Ω

R' = R1 + R2

R' = (6 + 6)Ω

R' = 12Ω

1/R = 1/R' + 1/R3

1/R = (1/12 + 1/6)Ω

1/R = 1/4Ω

R = 4Ω.