Question

An electric heater of resistance 8 ohm draws 15A current for 2 hours.
Calculate the heat developed in
the resistor.​

Answer 1

Answer:

The heat developed in the resistor is 3600J.

Step-by-step explanation:

Given :

• An electric heater of resistance 8 Ω draws 15 A current for 2 hours.

To calculate :

• The heat developed in the resistor.

Calculation :

Given that,

• Resistance = 8 Ω (ohm)
• Current = 15 Ampere
• Time taken = 2 hours

Using formula,

• Q = I²RT

Where,

• Q denotes heat = unknown
• I denotes current = 15 Ampere
• R denotes resistance = 8 Ω
• T denotes time taken = 2 hours

Plugging the values in the equation,

→ Q = 15² × 8 × 2

→ Q = (15 × 15) × 8 × 2

→ Q = 225 × 8 × 2

→ Q = 3600 J

Therefore, heat developed in the resistor is 3600 J.

Answer 2

Answer:-

• Resistance=R=8ohm
• Current=15A=I
• Time=t=2hours
• Heat=H=?

We know that

• Joule's Law States that,

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

$\\ \qquad\quad\sf\Rrightarrow Heat=15^2\times 8\times 2$

$\\ \qquad\quad\sf\Rrightarrow Heat=225\times 8\times 2$

$\\ \qquad\quad\sf\Rrightarrow Heat=1800\times 2$

$\\ \qquad\quad\sf\Rrightarrow Heat=3600J$

$\\ \qquad\quad\sf\Rrightarrow Heat=3.6\times 10^3J$

$\\ \qquad\quad\sf\Rrightarrow Heat=3.6KJ$

Henceforth

Heat developed in the heater is 3.6Kilo joules.