NEET Physics Calorimetry and Heat Transfer MCQs Set A

Question. Heat is transmitted from higher to lower temperature through actual mass motion of the molecules in
(a) convection
(b) None of these
(c) conduction
(d) radiation

Answer: A

Question.  Good absorbers of heat are
(a) good emitters
(b) poor emitters
(c) non-emitters
(d) highly polished

Answer: A

Question. Three bodies A, B and C have equal area which are painted red, yellow and black respectively. If they are atsame temperature, then
(a) emissive power of C is maximum.
(b) emissive power of A, B and C are equal
(c) emissive power of B is maximum
(d) emissive power of A is maximum.

Answer: A

Question. Sweet makers do not clean the bottom of cauldron because
(a) black and rough surface absorbs more heat
(b) transmission power of black and rough surface is more.
(c) absorption power of black and bright surface is more
(d) emission power of black and bright surface is more

Answer: A

Question. 4200 J of work is required for
(a) increasing the temperature of 100 g of water through 10°C
(b) increasing the temperature of 1 kg of water through 10°C
(c) increasing the temperature of 500 g of water through 10°C
(d) increasing the temperature of 10 g of water through 10°C

Answer: A

Question. The latent heat of vaporization of a substance is always
(a) greater than its latent heat of fusion
(b) greater than its latent heat of sublimation
(c) equal to its latent heat of sublimation
(d) less than its latent heat of fusion

Answer: A

Question. Which of the following statements regarding specific heat capacity of a substance are correct ? It depends on
I. mass of substance.
II. nature of substance.
III. temperature of substance.
IV. volume of substance
(a) II and III
(b) I and IV
(c) I and II
(d) III and IV

Answer: A

Question. A quantity of heat required to change the unit mass of a solid substance, from solid state to liquid state, while the temperature remains constant, is known as
(a) latent heat of fusion
(b) sublimation
(c) hoar frost
(d) latent heat

Answer: A

Question. Which of the following is used as a coolent in automobile radiator as well as a heater in hot water bags?
(a) Water
(b) Ice
(c) Sand
(d) All of these

Answer: A

Question. 500 g of water and 100 g of ice at 0°C are in a calorimeter whose water equivalent is 40 g. 10 g of steam at 100°C is added to it. Then water in the calorimeter is : (Latent heat of ice = 80 cal/g, Latent heat of steam = 540 cal/ g)
(a) 590 g
(b) 600 g
(c) 610 g
(d) 580 g

Answer: A

Question. Consider the following statements and select the correct statement(s).
I. Water and ice have same specific heats
II. Water and ice have different specific heats
III. Specific heat of water is more than that of ice
IV. Specific heat of ice is more than that of water
(a) II only
(b) III and IV
(c) I only
(d) II and III

Answer: A

Question. Assuming no heat losses, the heat released by the condensation of x g of steam at 100°C can be used to convert y g of ice at 0°C into water at 100°C, the ratio x : y is :
(a) 1 : 3
(b) 3 : 1
(c) 1 : 2
(d) 1 : 1

Answer: A

Question. A lead bullet strikes against a steel plate with a velocity 200 m s^–1. If the impact is perfectly inelastic and the heat produced is equally shared between the bullet and the target, then the rise in temperature of the bullet is (specific heat capacity of lead = 125 J kg^–1 K^–1)
(a) 80°C
(b) 60°C
(c) 160°C
(d) 40°C

Answer: A

Question. Certain amount of heat is given to 100 g of copper to increase its temperature by 21° C. If the same amount of heat is given to 50 g of water, then the rise in its temperature is (Specific heat capacity of copper = 400 J kg^–1 K^–1 and that for water = 4200 J kg^–1 K^–1)
(a) 4° C
(b) 5.25° C
(c) 8° C
(d) 6° C

Answer: A

Question. A hammer of mass 1 kg having speed of 50 m/s, hit a iron nail of mass 200 gm. If specific heat of iron is 0.105 cal/gm°C and half the energy is converted into heat. the raise in temperature of nail is
(a) 7.1°C
(b) 9.2°C
(c) 10.5°C
(d) 12.1°C

Answer: A

Question. In an energy recycling process, 100 g of steam at 100°C becomes water at 100°C which converts y g of ice at 0°C into water at 100°C. The numeric value of y is
(a) 300
(b) 400
(c) 200
(d) 100

Answer: A

Question. In a water-fall the water falls from a height of 100 m. If the entire K.E. of water is converted into heat, the rise in temperature of water will be
(a) 0.23°C
(b) 0.46°C
(c) 2.3°C
(d) 0.023°C

Answer: A

Question. 19 g of water at 30°C and 5 g of ice at – 20°C are mixed together in a calorimeter. What is the final temperature of the mixture? Given specific heat of ice = 0.5 cal g^–1(°C)^–1 and latent heat of fusion of ice = 80 cal g^–1
(a) 5°C
(b) 10°C
(c) –5°C
(d) 0°C

Answer: A

Question. A 2 kg copper block is heated to 500°C and then it is placed on a large block of ice at 0°C. If the specific heat capacity of copper is 400 J/kg°C and latent heat of fusion of water is 3.5 × 10⁵ J/kg, the amount of ice that can melt is
(a) (8/7) kg
(b) (5/7) kg
(c) (7/5) kg
(d) (7/8) kg

Answer: A

Question. Two spheres of different materials one with triple the radius and one-fifth wall thickness of the other are filled with ice. If the time taken for complete melting of ice in the larger sphere is 30 minute and for smaller one is 20 minute, the ratio of thermal conductivities of the materials of larger spheres to that of smaller sphere is
(a) 1/2
(b) 2/3
(c) 3/4
(d) 1/8

Answer: A

Question. Ice starts forming in a lake with water at 0ºC when the atomspheric temperature is –10ºC. If the time taken for the first 1 cm of ice to be formed is 7 hours, then the time taken for the thickness of ice to change from 1 cm to 2 cm is
(a) 21 hours
(b) 7 hours
(c) 14 hours
(d) 3.5 hours

Answer: A

Question. A kettle with 3 litre water at 27°C is heated by operating coil heater of power 2 kW. The heat is lost to the atmosphere at constant rate 130J/sec, when its lid is open. In how much time will water heated to 97°C with the lid open? (specific heat of water = 4.2 kJ/kg)
(a) 472 sec
(b) 912 sec
(c) 693 sec
(d) 1101 sec

Answer: A

Question. The two ends of a metal rod are maintained at temperatures 100°C and 110°C. The rate of heat flow in the rod is found to be 4.0 J/s. If the ends are maintained at temperatures 200°C and 210°C, the rate of heat flow will be
(a) 4.0 J/s
(b) 44.0 J/s
(c) 8.0 J/s
(d) 16.8 J/s

Answer: A

Question.  Four identical rods of same material are joined end to end to form a square. If the temperature difference between the ends of a diagonal is 100°C, then the temperture difference between the ends of other diagonal will be
(a) 0°C
(b) 100°C
(c) Both
(d) None of these

Answer: A

Question.  300 gm of water at 25°C is added to 100 g of ice at 0°C. The final temperature of the mixture is
(a) 0°C
(b) 5°C
(c) 15°C
(d) 25°C

Answer: A

Question. A slab of stone of area 0.36 m2 and thickness 0.1 m is exposed on the lower surface to steam at 100°C. A block of ice at 0°C rests on the upper surface of the slab. In one hour 4.8 kg of ice is melted. The thermal conductivity of slab is :
(Given latent heat of fusion of ice = 3.36 × 10⁵ J kg^–1.) :
(a) 1.24 J/m°C
(b) 2.05 J/m°C
(c) 1.29 J/m°C
(d) 1.02 J/m°C

Answer: A

Question. A piece of ice falls from a height h so that it melts completely. Only one-quarter of the heat produced is absorbed by the ice and all energy of ice gets converted into heat during its fall. The value of h is : [Latent heat of ice is 3.4 × 10⁵ J/kg and g = 10 N/kg] 
(a) 136 km
(b) 68 km
(c) 544 km
(d) 34 km

Answer: A

Question. A partition wall has two layers of different materials A and B in contact with each other. They have the same thickness but the thermal conductivity of layer A is twice that of layer B. At steady state the temperature difference across the layer B is 50 K, then the corresponding difference across the layer A is
(a) 25 K
(b) 60 K
(c) 12.5 K
(d) 50 K

Answer: A

Question. The tempertaure of equal masses of three different liquids A, B and C are 12°C, 19°C and 28°C respectively. Thetemperature when A and B are mixed is 16°C and when B and C are mixed is 23°C . The temperature when A and C are mixed is
(a) 20.2°C
(b) 25.2°C
(c) 22°C
(d) 18.2°C

Answer: A

Question. The tempertaure of equal masses of three different liquids A, B and C are 12°C, 19°C and 28°C respectively. Thetemperature when A and B are mixed is 16°C and when B and C are mixed is 23°C . The temperature when A and C are mixed is
(a) 20.2°C
(b) 25.2°C
(c) 22°C
(d) 18.2°C

Answer: A