Previous year questions with solutions · 2024 – 2026
| Year | Questions | Papers | Avg / paper | Weightage |
|---|---|---|---|---|
| 2026 | 10 | 19 | 0.53 | 2.11% ▼ 28.6% vs last year |
| 2025 | 14 | 19 | 0.74 | 2.95% ▲ 784.2% vs last year |
| 2024 | 2 | 20 | 0.1 | 0.33% |
The heat extracted out of x gram of water initially at 50 °C to cool it down to 0 °C is sufficient to evaporate (1000-x) gram of water also initially at 50 °C. The value of x (closest integer) is . (Take latent heat of water 2256 kJ/kg, specific heat capacity of water 4200 J/kg. K)
A gas of certain mass filled in a closed cylinder at a pressure of 3.23 kPa has temperature 50 . The gas is now heated to double its temperature. The modified pressure is Pa.
A wire of length 10 cm and diameter 0.5 mm is used in a bulb. The temperature of the wire is 1727 and power radiated by the wire is 94.2 W. Its emissivity is x8 where x = . (Given = 6.0 10-8 W m-2 K-4, = 3.14 and assume that the emissivity of wire material is same at all wavelengths.)
Two cylindrical rods A and B made of different materials, are joined in a straight line. The ratios of lengths, radii and thermal conductivities of these rods are: LALB = 12, rArB = 2 and KAKB = 12. The free ends of rods A and B are maintained at 400 K, 200 K, respectively. The temperature of rods interface is K, when equilibrium is established.
Three conductors of same length having thermal conductivity k1,k2 and k3 are connected as shown in figure. [figure] Area of cross sections of 1st and 2nd conductor are same and for 3rd conductor it is double of the 1st conductor. The temperatures are given in the figure. In steady state condition, the value of is . (Given : k1=60 Js-1 m-1 K-1, k2=120 Js-1 m-1 K-1, k3=135 Js-1 m-1 K-1 )