Heat is being supplied at a constant rate to a sphere of ice which is melting at the rate of 0.1 gm / sec. It melts completely in 100 sec. The rate of rise of temperature thereafter will be (Assume no loss of heat)

Question

Heat is being supplied at a constant rate to a sphere of ice which is melting at the rate of 0.1 gm / sec. It melts completely in 100 sec. The rate of rise of temperature thereafter will be (Assume no loss of heat) (A) 0.8° C / sec (B) 5.4° C / sec (C) 3.6° C / sec (D) will change with time

Tardigrade Admin · Accepted Answer

Required heat/sec =0.1 × 80 cal / gm =8 cal / sec Produced mass =0.1 × 100=10 gm ice or water [ now Q = ms Δ T ] In unit time rise of temperature will be Δ T = Q / ms =8 /(10 × 1)=0.8° C / s

Q. Heat is being supplied at a constant rate to a sphere of ice which is melting at the rate of $0.1 g m / sec$ . It melts completely in $100 sec$ . The rate of rise of temperature thereafter will be (Assume no loss of heat)

$0. 8^{\circ} C / sec$

$5. 4^{\circ} C / sec$

$3. 6^{\circ} C / sec$

will change with time

Required heat/sec $= 0.1 \times 80 c a l / g m$
$= 8 c a l / sec$
Produced mass $= 0.1 \times 100 = 10$
$g m$ ice or water $[$ now $Q = m s Δ T]$
In unit time rise of temperature will be
$Δ T = Q / m s = 8/ (10 \times 1) = 0. 8^{\circ} C / s$

Q. Heat is being supplied at a constant rate to a sphere of ice which is melting at the rate of 0.1gm/sec. It melts completely in 100sec. The rate of rise of temperature thereafter will be (Assume no loss of heat)

0.8∘C/sec

5.4∘C/sec

3.6∘C/sec