Question

star potential difference between the terminals of a electric heater is 60 v when it drawn a current of 4A from the source what current will the heater draw if the potential difference is increased to 120v​

Answer 1

$\underline{\sf{\blue{\:\:\:\:Given:-}}}$

Potential difference (V)= 60V

And Current (I)= 4A

To Find :-

The current when it's potential difference is increase to 120 V

Now

Note :-

Rate of flow of charge is called current .

It's S.I unit is Ampere

A.T.Q :-

$\boxed{\sf{\dag{\:\: Potential\: difference (V)= Current (I)\times Resistance (R)}}}$

Now find the resistance

$\sf\implies R=\dfrac{V}{I}\\ \\ \sf\implies R= \cancel{\dfrac{60V}{4A}}\\ \\ \sf\implies Resistance (R)= 15ohm$

Now calculate the Current if potential difference is increase to 120V

So it's resistance remains same

• Calculate the Current (I)

$\sf\implies V=IR\\ \\ \sf\implies Current (I)=\dfrac{Potential\: difference (V)}{Resistance(R)}\\ \\ \sf\implies I=\cancel{\dfrac{120}{15}}\\ \\ \sf\implies I= 8A$

$\boxed{\sf{\bullet {\: Current\:(I)=8 \: Amperes}}}$

Answer 2

Answer :

8 A

Solution :

Potential difference between the terminals of an electric heater ( V ) = 60 V

Current drawn from the source ( I ) = 4 A

We know that :

Resistance ( R ) = V / I

⇒ R = 60 / 4

⇒ R = 15 Ω

When pottential difference is increased to 120 V

Potentianl difference between the terminals of an electric heater ( V ) = 120 V

Current ( I ) = ?

Resistance ( R ) = 12 Ω

Resistance remain same as it is a proportionality constant

⇒ R = V / I

⇒ 15 = 120 / I

⇒ I = 120 / 15 = 8 A

Therefore the current drawn by the heater is 8 A.