Question

4) 2A current flows through an electrical heating device of resistance 100 Ω.The time required to produce 50000 J heat is

2 points

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Answer 1

$\mathcal{\green{\underline{\red{GIVEN:}}}}$

• Current (I) = 2A.
• Resistance (R) = 100 Ω.
• Heat energy (H) = 50000 J.

$\mathcal{\green{\underline{\red{TO \:\: FIND:}}}}$

• We need to find the time (t).

$\mathcal{\green{\underline{\red{SOLUTION:}}}}$

We have to use the heat energy formula, i.e.,

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

Where t is time. Substitute the values in the equation.

$\sf 50000=2^2 \times 100 \times t$

$\sf \to t=\dfrac{50000}{4 \times 100}$

$\to \sf{\pink{t=125 \: seconds.}}$

∴TIME TAKEN TO PRODUCE 50000 J OF HEAT ENERGY IS 125 SECONDS.

$\mathcal{\green{\underline{\red{LEXICAL \:\: TERMS:}}}}$

• When current flows through a conductor, heat is produced. In other words, some electrical energy is converted into heat energy.
• It is used in electric irons, bulbs, Electric heaters, Electric fuses.
• Factors affecting heat energy:

⇒Resistance ∝ Heat energy.

⇒Time ∝ Heat energy

⇒Current ∝ Heat energy.

• Sometimes this heat energy is undesirable because it converts useful electrical energy into heat.