Question

Three resitors r½ampere 4 ampere are connected in series in a circuit if the result resistance in the circuit is 20 ampere. find the value of R​

Answer 1

Answer:

ANSWER

The current in the circuit is calculated from the formula I=

R+r

ε

where,

ε- emf of the cell

R- external resistance

r- internal resistance of the cell.

When the cell of internal resistance of 3 ohms and the total current in the circuit is given as 0.25 A the current relation is given as

That is, 0.25=

R+3

2

.

The Resistance is R=5Ω

Hence, the total resistance in the circuit is 5 ohms, out which one resistor is 4 ohms. So, the unknown combined resistance is 5−4=1Ω.

The potential difference across the 2 ohms or R resistor is given as V=IR=0.25A×1Ω=0.25V

Thus, the p.d. across the R or 2 ohms resistor is 0.25 V.