Question

If the wires a and b has a resistance of 5 ohm and 10 ohm respectively. calculate the ratio ofor the combination of series and parallel combination.

Answer 1

for parallel combination
R=5×10/5+10
=50/15=3.3
for series combination
r=5+10=15
R/r=3.3/15

Answer 2

For series combination resistance directly add up
S=5+10=15 ohm

For parallel combination resistance add inversely
1/P=1/5+1/10=2/10+1/10=3/10
P=10/3 ohm

Now the ratio S/P=15×3/10=9/2=4.5

Hope it will work for you