Question

Calculate the heat generated in joule in a coil
when potential difference of 30 volts is applied
across it. The current of 0.8 A is passed for 4
minutes.​

Answer 1

Answer :

• Heat energy generated in the coil is 5760 J.

Explanation :

Given :

• Potential difference of the coil, V = 30 V
• Current flowing in the coil, I = 0.8 A
• Time taken for flow of current, t = 4 min or 240 s.

To find :

• Heat energy generated in the coil, H = ?

Knowledge required :

• Formula for heat energy in a electric current :

⠀⠀⠀⠀⠀⠀⠀⠀⠀H = I²Rt⠀

[Where : H = Heat energy generated, I = Current flowing in the circuit, R = Resistance in the circuit, t = time taken]

• Ohm's law :

⠀⠀⠀⠀⠀⠀⠀⠀⠀V = IR⠀

[Where : V = Potential difference of the circuit, I = Current flowing in the circuit, R = Resistance in the circuit]

From the ohm's law, we get :

⠀⠀=> V = IR

⠀⠀=> V/I = R

⠀⠀⠀⠀⠀∴ R = V/I

So the formula for resistance is V/I.

Now substituting the value of resistance in the circuit, we get :

⠀⠀=> H = I²Rt

⠀⠀=> H = I²(V/I)t

⠀⠀⠀⠀⠀∴ H = I²(V/I)t

Solution :

By using the formula for heat energy generated and substituting the values in it, we get :

⠀⠀=> H = I²(V/I)t

⠀⠀=> H = 0.8² × 30/0.8 × 240

⠀⠀=> H = 0.8 × 30 × 240

⠀⠀=> H = 8/10 × 30 × 240

⠀⠀=> H = 8/10 × 7200

⠀⠀=> H = 8 × 720

⠀⠀=> H = 5760

⠀⠀⠀⠀⠀∴ H = 5760 J

Therefore,

• Heat energy generated in the coil, H = 5760 J

Answer 2

$\huge{\boxed{\bold{Question}}}$Calculate the heat generated in joule in a coil

when potential difference of 30 volts is applied

across it. The current of 0.8 A is passed for 4

minutes.

$\huge{\boxed{\bold{Answer}}}$

V=Potential different of the circuit.

I=Corrent flowing in the circuit.

R=Resistance in the Circuit.

OHM law

$\longmapsto \mathfrak{v = ir} \\ \\ \longmapsto \mathfrak{ \frac{v}{r} = r} \\ \\ \longmapsto \mathfrak{ \therefore \: r = \frac{v}{i} }$

So the formula =V/I

The value of resistance in the current we get.

$\implies \rm \: h = {i}^{2} rt \\ \\ \\ \implies \rm \: h = {i}^{2} ( \frac{v}{i} )t \\ \\ \\ \tt \therefore= {i}^{2} ( \frac{v}{i}) t \\ \\ \\ \\ \leadsto \rm \: h = {i}^{2} ( \frac{v}{i} )t \\ \\ \\ \leadsto \rm \: h = 0. {8}^{2} \times \frac{30}{0.8} \times 240 \\ \\ \\ \leadsto \rm \: h = 0.8 \times 30 \times 240 \\ \\ \\ \leadsto \rm \: h = \frac{8}{10} \times 30 \times 240 \\ \\ \\ \leadsto \rm \: h = \frac{8}{10} \times 7200 \\ \\ \\ \leadsto \rm \: h = 8 \times 720 \\ \\ \\ \leadsto \rm \: h = 5760 \\ \\ \longmapsto \bullet \mathfrak{ h = 5760 \: j} \\ \\ \\ {\boxed{ \boxed{ \boxed{ \mathfrak{the \: \: answer \: \: is \: \: 5760}}}}}$