Question

A man have five resistors each of value 0.2 ohms. the maximum resistance he can obtain by connecting them will be

Answer 1

He can connect those five resistors in two ways,

Parallel R = r1+ r2

Series 1/R = 1/r1 + 1/r2

1) Parallel :

1/R1 = (1/0.2 × 5) [because 5 of them has same resistance value]

1/R1 = 25

R1 = 1/25

2) Series:

R2 = (0.2 × 5)[because 5 of them has same resistance value]

R2 = 1

Now , R2 > R1

So, if he connects those resistors into series connection ,then he will get the maximum amount of resistance output.

Answer 2

Answer:

he has to connect them in series

Explanation:

to get the maximum resistance the man has to connect all five resistors in parallel

R1 = 0.2 OHM

R2  = 0.2 OHM

R3 = 0.2 OHM

R4 = 0.2 OHM

and R5  = 0.2 OHM

 hence 1/Req = 1/R1 +1/R2+1/R3+1/R4+1/R5

                    = 1/2/10+ 1/2/10+ 1/2/10+ 1/2/10+ 1/2/10

                  = 50/2

                   = 25 ohms