Question

Find the effective resistance of the following ​

Answer 1

Answer:

1. 60 ohm

2. 0.53 ohm

3. 5.2 ohm

Answer 2

Answer

1. 60ohm

2. 1.75ohm

3. 9ohm

Explanation:

1. The resistance R1 , R2 and R3 are in series combination.

therefore effective resistance ,R = R1+R2+R3

= 10+ 20+30

=60 ohm

2. R1= 5ohm

R2= 3 ohm

R1 and R2 are in parallel combination

therefore effective resistance =

1/R = 1/R1 +1/R2

1/R = 1/5 + 1/3

R = 15/8

R = 1.75 ohm

3. R1=R2=10 ohm

R3= 5 ohm

R4= 3ohm

R5= 2 ohm

Now R1 and R2 are in series combination

therefore net resistance, R' = 10+10

=20ohm

Now this R' is in parallel combination with R3

therefore net resistance , 1/R'' = 1/R' + 1/R3

1/R'' = 1/20 + 1/5

R"= 20/5 = 4ohm

Now R",R4,R5 are in series combination

therefore effective resistance of circuit,

R= R"+R4+R5

= 4+3+2= 9 ohm