Question

Consider the circuit shown in the figure below. (Let R = 26.0 ohm.)  Find the current in the 26.0-OHM resistor.  Compare the potential difference across the 10-ohm resistor, the  Find the potential difference between points a and b.  Is it possible for the potential difference across any element

Answer 1

5 and R are in series, so equivalent of these two resistor is R'.

then R' = 5+ R = 31 ohm

now R', 5 ohm and 10 ohm are in parallel

1/R" = 1/R' + 1/5 + 1/10 =1/31 + 1/5 + 1/10

R" = 3 ohm

now R" and top 10 ohm are in series.

Req = R" + 10 = 13 ohm

current through battery, I = V/Req = 25/13 = 1.923 A

PD across each branch will be same and V = 25 - 10I =25 - 10(1.923) = 5.77 Volt

a) PD across R' is 5.77 V

current through 5 and R is 5.77 / 31 = 0.186 A .........Ans

b) Vab = 5.77 Volt