Question

A bucket contains a mixture of water and ice and total mass of content is 10 kg. Now this mixture is provided heat at uniform rate. The temperature Vs time graph is plotted. The initial amount of ice in the bucket will be [specific heat of water = 4.2 kJ/kg-K and latent heat of ice = 340 kJ/kg] –

• A. 1.2 kg
• B. 2.4 kg
• C. 5 kg
• D. 5.2 kg

Answer 1

Answer: (A)

1.2 kg

Answer 2

Let P be the rate of heat supplied.

P × 50 × 60 = m × 340 × 10³ … (1)

P × 10 × 60 = 10 × 4.2 × 10³ × 2 … (2)

For (1) & (2),

$\frac{50}{10}$=$\frac{m \times 340}{20 \times 4.2}$

̃ m =$\frac{50 \times 20 \times 4.2}{10 \times 340}$̃ 1.2 kg