Question

fast !! A potential difference of 100V is applied to a 20 Ω resistor for 5 minutes. What is the amount of heat generated?

Answer 1

Answer:

Given potential difference V = 100volts,

Resistance of the resistor, R = 50ohms.

So power produced in the circuit , P =(V^2)/R

i.e. P = 100*100/50 = 200 watt = 200 J/s.

But we know, P = energy/ time

So, energy = power * time

Time should be taken in it's standard units i.e seconds

6min 58 seconds = (6*60)+58 = 418 seconds.

Energy = (200 *418)J = 83,600J

We know that 1calorie = 4.184J

So, energy= (83,600)/4.184 = 19,980.87 calories.

Final answer :-(1) energy = 83,600 J

(2) energy = 19,980.87 calories.

Hope this helps.

Answer 2

Answer:-

• Potential Difference=100V=V
• Resistance=R=20ohm
• Time=5min=300s
• Heat=H=?

Finding Current:-

$\boxed{\sf \dfrac{V}{I}=R}$

$\\ \sf\longmapsto I=\dfrac{V}{R}$

$\\ \sf\longmapsto I=\dfrac{100}{20}$

$\\ \sf\longmapsto I=5A$

Now

According to Joules law

$\boxed{\sf H=I^2Rt}$

$\\ \sf\longmapsto H=5^2\times 20\times 300$

$\\ \sf\longmapsto H=25\times 20\times 300$

$\\ \sf\longmapsto H=500\times 300$

$\\ \sf\longmapsto H=15000J$

$\\ \underline{\boxed{\bf{\therefore Heat\:Generated=15000J}}}$