Question

A current 3 amp flows through a 10 ohm resistor . The energy dissipated in 5 minutes will be​

Answer 1

27000 joules is the required answer.

GIVEN:

• Current , I = 3 A

• Resistance, R = 10 ohm

• Time , t = 5 minutes

TO FIND:

Energy dissipated, H

FORMULA:

Here the energy is released in the form of heat.

According to joule's law of heating,

H = I²Rt

SOLTUION:

STEP 1 : TO CONVERT TIME IN STANDARD UNITS:

• The standard unit of time is second.

• 1 minute = 60 seconds.

• 5 minutes = 5 × 60 seconds

• Time, t = 300 seconds

STEP 2 : TO FIND ENERGY DISSIPATED:

H = I²Rt

H = 3² × 10 × 300

H = 9 × 3000

H = 27000 J

H = 27 × 10³ J

H = 27 kilo joule

ANSWER:

Energy dissipated in 5 minutes is 27000 joule.

JOULE'S LAW OF HEATING:

When current I passes through a conductor of resistance R for a time t , the heat produced ,H of directly proportional to the resistance , time and square of current .

The energy is dissipated due to the resistance offered by resistor to the flow of current.

Joules law of heating finds application in electric iron , welding rods, etc.