Question

100J heat is generated in a resistance of 4ohm in 1 second.What is the potential difference of the resistor?

Answer 1

V= 20 ohms.

we have resistance, heat and time given in the statement but we don't have current, which is very important to calculate the potential difference. So we will find current firstly and then the potential difference

Explanation:

H = I²RT

I = √(H/RT)

I = √( 100/4)

I = 5 A

now. V = IR

so, V= 5(4)

V= 20 ohms

Answer 2

Given :-

☄ Heat generated in a resistance,h = 100 J

☄ Time taken,t = 1 second

☄ Resistance across the resistor, r = 4 ohm

To find :-

Potential difference across the resistor

Solution :-

using joules law of heating that is

$\bigstar$The heat produced in a wire is directly proportional to square of current, resistance of wire and time for which the current is passed .i.e.,

$\dashrightarrow \bf H = {I}^{2} Rt</p><p></p><p>$

$\dashrightarrow{\sf{100 = (I)^2 ( 4 )(1)}}$

$\dashrightarrow{\sf{100 =( I)^2 ( 4) }}$

$\dashrightarrow{\sf{I^2 = \dfrac{100}{4}}}$

$\dashrightarrow{\sf{I^2 = 25}}$

$\dashrightarrow \bf I = 5A$

now, Using ohm's law .i.e.,

$\bigstar$The potential difference,V, across the ends of the given metallic wire in an electric circuit is directly proportional to the current flowing through it, provided it's temperature remains the same

ln other words ,

$\dashrightarrow\bf V = IR$

$\dashrightarrow\sf{V =( 5 )(4)}$

$\dashrightarrow \bf V = 20V$

thus, the potential difference across the resistor is 20 V.

$\:$

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