Question

explain effect of temperature on resistance.The heating element connected to 220 V drawsa Determine the amount of heat dissipated in 15 minute. J=4.2 JKal​

Answer 1

$\bold{RESISTANCE}$

Resistance is the obstruction offered in the path of current. This is caused due to the collision of the electrons with the other electrons or protons.

$\bold{Effect \: of \: temperature \: on \: resistance}$

The more will be the temperature the more will be kinetic energy so the random movement will also increases. So, the more will be the collision the more will be the resistance.

So, we can convey that resistance increases with increase in temperature.

Given,

Time = 15 min

In hours it will be ,

$\dfrac{15}{60} = \dfrac{1}{4}$

Heat energy = 4.2 joules Kal

We know,

$\large \boxed{\mathsf{H = \dfrac{VI^{2}t}{100}}}$

$\mathsf{4.2= \dfrac{220 \times I^{2} \times 1 }{1000 \times 4}}$

$\mathsf{16800 = 5500 \times I^{2}}$

$\mathsf{\dfrac{16800}{5500} = I^{2}}$

$\mathsf{3.0545 = I^{2}}$

$\mathsf{\sqrt{3.0545} = I}$

$\large \boxed{\mathsf{I = 1.7477 A}}$