Exams › JEE Main › Physics

Steam is added to 100 g of water to raise its temperature from 24 deg C to 90 deg C. Calculate the mass of steam required. (Latent heat of steam = 540 cal/g, specific heat of water = 1 cal/g/deg C; steam condenses at 100 deg C and the condensed water cools to 90 deg C.)

1. 10 g
2. 12 g
3. 15 g
4. 20 g

Correct answer: 12 g

Solution

Equating heat gained by water (6600 cal) to heat released by steam (550 cal per gram) gives about 12 g of steam.

Related JEE Main Physics questions

• A cube initially at 0°C is subjected to the same external pressure P on all its faces, causing it to be compressed. How much must its temperature be increased so that the cube regains its original size? The bulk modulus of the cube material is B and its coefficient of linear expansion is α.
• If λm represents the wavelength at which a black body emits radiation most strongly at temperature T K, then which relation is true?
• Which of the following statements about heat transfer is/are incorrect?
• A composite wall consists of two slabs, A and B, of equal thickness but made of different materials. Their thermal conductivities satisfy K_A = 3K_B. If the total temperature difference across the wall is 20°C, then in steady thermal equilibrium:
• An evacuated bulb contains a filament that is 10 cm long and 0.2 mm in diameter. If its emissivity is 0.2, determine the radiant power emitted by the filament at 2000 K. Take σ = 5.67 × 10⁻⁸ W/m² K⁴.
• A rectangular solid is raised in temperature from 0°C to 100°C. If its length increases by 0.10% over this interval, what is the corresponding percentage increase in its volume?

⚔️ Practice JEE Main Physics free + battle 1v1 →