CBSE
Multiple Choice Questions5 g of ice of O°C is dropped in a beaker containing 20 g of water at 40°C. The final temperature will be
32°C
16°C
8°C
24°C
A cup of tea having the temperature 80°C is kept in a room,which is at 20°C. Which of the given curves best represents the variation of temperature T of the cup with time t ?
Colour of a star indicates its
density
distance
energy
temperature
The amount of heat required to change 1 g (0°C) of ice into water of 100°C, is
716 cal
500 cal
180 cal
100 cal
Value of - 40°C in Fahrenheit scale is
- 40F
32 F
- 32 F
40°C
According to Newton's law of cooling, the rate of cooling of a body is proportional to (Δθ)n, where Δθ is the difference of the temperature of the body and the surroundings, and n is equal to
2
3
4
1
If temperature of an object is 140°F, then its temperature in centrigrade is
105°C
32°C
140°C
60°C
An ice box made of Styrofoam (thermal conductivity = 0.01 Jm-1s-1K) is used to keep liquids cool. It has a total wall area including lid of 0.8 m2 and wall thickness of 2.0 cm. A bottle of water is placed in the box and filled with ice. If the outside temperature is 30°C, the rate of flow of, heat into the box is (in Js-1)
16
14
12
10
An electric heater of resistance 6 Ω works for 10 min on a 60 V line. The energy liberated in this period of time is
7.2 × 103 J
3.6 × 105 J
43.2 × 104 J
28.8 × 104 J
Which of the following has maximum specific heat?
Water
Alcohol
Glycerene
Oil
