Question

Can someone solve this numerical with proper working.....

PLEASE !!!!!!​

Answer 1

Case 1 :-

Voltage = 220 volts.

Time (T1) = 5 minutes.

It takes 5 minutes to reach its boiling point.

So,

Let the Boiling point be H

Now,

We already know that :-

$\boxed{p = \frac{ {v}^{2} }{r} }$

Now,

We know that

$\boxed{heat = power \times time}$

So,

H = P* t

So,

$\boxed{h =\dfrac{{v}^{2} }{r} \times t}$

Now in case 1 it will be :-

$\mathcal{heat = \dfrac{ {(v1)}^{2} }{r} \times 5} = \frac{ {(220)}^{2} }{r} \times 5$

Now,

In second case :-

Voltage = 200 volts

The Boiling point will remain the same in this case also.

So,

Now,

Again the same formula will be applied :

H = Power * time

Or,

$\boxed{h = \frac{ {(v2)}^{2} }{r} \times t2} \\ \\ =\boxed{h = \frac{ {(200)}^{2} }{r} \times t2}$

Where t2 is the time required for the kettle to reach its boiling point when voltage is 200 volt

So,

From the above two cases we get the following :-

$\boxed{\frac{ {(220)}^{2} }{r} \times 5 = \frac{ {(200)}^{2} }{r} \times t2}$

So,

On simplifying :-

$t2 = \frac{220 \times 220 \times 5}{200 \times 200} \\ \\ \\ t2 = 6.05 \: minutes$

Answer!