# The number of quanta of radiations of $V=4.67\times10^{13}$ HZ that must be absorbed in order to melt 5g of ice is (the energy required to melt 1g of ice is 333 J) Option 1) $5.38\times10^{22}$ Option 2) $30.9\times10^{21}$ Option 3) $4.67\times10^{13}$ Option 4) $6.62\times10^{34}$

V Vakul

As we learnt in

The energy (E) of a quantum of radiation -

$E=hv$

Where h is plank’s constant and $\nu$ is frequency

-

Energy required=$5\times 333\, \, J$

$n\times h\times v=5\times 333J\\*\\*n=\frac{5\times 333}{4.67\times 10^{13}\times 6.62\times 10^{-34}}=5.38\times 10^{22}$

Option 1)

$5.38\times10^{22}$

Correct

Option 2)

$30.9\times10^{21}$

Incorrect

Option 3)

$4.67\times10^{13}$

Incorrect

Option 4)

$6.62\times10^{34}$

Incorrect

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