Question

Two resistors of 5 ohm and 10 ohm are connected in parallel.8 such sets are connected in series.find the equivalent resistance.

Answer 1

Resistance connected in parallel

1/Rp =1/R1+1/R2

=1/5+1/10

=3/10

Now 8 such sets are connected in series

So= 3/10*8=24/10

=2.4

Answer 2

Given: Parallel resistors arrangement

           R₁ = 5 ohm

           R₂ = 10 ohm

           Such 8 sets connected in series.

To FInd: Equivalent resistance = R

Solution:

Formulas used:

Equivalent resistance for parallel resistors - R'

1/R' = 1/R₁ + 1/R₂

Equivalent resistance for resistors connected in series - R''

R'' = R₁ + R₂

Note:  The Equivalent resistance of two resistors of 5 ohms and 10 ohms connected in parallel would then be series to each other when 8 such sets are connected.

Applying the above formulas:

1/R' = 1/R₁ + 1/R₂

     = 1/5 + 1/10

     =2 + 1/10

     = 3/10

R' = 10/3= 3.33

R for 8 such sets connected in series:

R = 8 × 3.33

   = 26.67 ohms

Hence the equivalent resistance of the given connection of resistors is 26.67 ohms.