Question

A DC voltage of 50V with 5Ω internal resistance is connected to 20Ω resistor.

Determine (a) the current and power taken by load resistor, (b) the value of

load resistance to absorb maximum power from the source​

Answer 1

Answer:

Let the emf of the battery be E.

Internal resistance of battery r=3Ω.

Voltage across the resistor 20Ω is 10 volts.

Voltage across resistor 20Ω V=

R+r

R

E

∴ 10=

20+3

20

E

⟹ E=11.5 volts

Now another resistor 30Ω is connected in series with battery and previous resistor.

Total resistance of the circuit R

eq

=30+20+3=53Ω

Current flowing through the circuit I=

R

eq

E

∴ I=

53

11.5

=0.22 A

Thus terminal potential difference across the combination V

′

=I(20+30)

∴ V

′

=0.22×50=11 volts