Photons absorbed in matter are converted to heat. A source emitting n photon/sec of frequency ν is used to convert 1kg of ice at 0°C to water at 0°C. Then, the time T taken for the conversion (a) decreases with increasing n, with ν fixed (b) decreases with n fixed, ν increasing (c) remains constant with n and ν changing such that nν = constant (d) increases when the product nν increases
Correct option is D) Energy spent to convert ice into water =mL=(1000g)×80calg−1=80000 cal Energy of photons used = nT×E=nT×hν ∴nTHν=mL orT=nHνmL ∴ T∝ν1 when n fixed. Thus T is constant if νis constant . Thus options(a), (b) and (c) are correct.
