Question

A 10-V battery supplies a constant current of 0.5 amp to a resistance for 30 min.

(a) Determine the resistance, in ohms.

(b) For the battery, determine the amount of energy transfer by work, in kJ.

Answer 1

Answer:

a)R=20 ohm

b)W= 9 KJ

Explanation:

Given that

Voltage difference ,ΔV= 10  V

Current ,I = 0.5 A

Resistance = R

time = 30 min = 30 x 60 s = 1800 s

a)

We know that

ΔV= I R

$R=\dfrac{10}{0.5}\ ohm$

R=20 ohm

b)

The power P = V I

P = 10 x 0.5 = 5 Watt      ( 1 watt = J/s)

We know that

$P=\dfrac{W}{t}$

W=work

t=time

W =  P t

W= 5 x 1800 J

W= 9000 J =9 KJ

W= 9 KJ