Question 255: Current Electricity

Question

A battery of 3.0 V is connected to a resistor dissipating 0.5 W of power. If the terminal voltage of the battery is 2.5 V, the power dissipated within the internal resistance is :

Accepted Answer

P
R
= 0.5 W
$$ \Rightarrow $$ i
2
R = 0.5 W
iR = 2.5
$$ \Rightarrow $$ i = 0.2 A & R = 12.5 $$\Omega $$
Also, V = E Ã¢ÂÂ ir
$$ \Rightarrow $$ 2.5 = 3 Ã¢ÂÂ (0.2)r
$$ \Rightarrow $$ r = 2.5 $$\Omega $$
Power dissipated in internal resistance
= i
2
r = (0.2)
2
(2.5) = 0.1 W

Answer

0.50 W

Answer

0.072 W

Answer

0.10 W

Answer

0.125 W

Current Electricity

A battery of 3.0 V is connected to a resistor dissipating 0.5 W of power. If the terminal voltage of the battery is 2.5 V, the power dissipated within the internal resistance is :

Choose the correct answer: