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Set 3 of 5 · Questions 61-90 of 145

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JEE Main Physics · Thermal Properties & Calorimetry · Set 3 (Q61-90)

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  1. 61.
    The sprinkling of water reduces slightly the temperature of a closed room because
    1. (1)temperature of water is less than that of the room
    2. (2)specific heat of water is high
    3. (3)water has large latent heat of vaporization
    4. (4)water is a bad conductor of heat.
  2. 62.
    1 gram of ice is mixed with 1 gram of steam. At thermal equilibrium, the temperature of the mixture is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  3. 63.
    A cup of tea cools from to in 1 minute in a room at . How long will it take to cool from to in the same room?
    1. (1)4 minutes
    2. (2)2 minutes
    3. (3)1 minute
    4. (4)3 minutes
  4. 64.
    1 kg of water at 100° C is converted into steam at 100° C by boiling at atmospheric pressure. The volume of water changes from 1.00 as a liquid to 1. 671 as steam. The change in internal energy of the system during the process will be (Given latent heat of vaporisation = 2257 kJ / kg, Atmospheric pressure = 1 x Pa)
    1. (1)-2426 kJ
    2. (2)+2090 kJ
    3. (3)-2090 kJ
    4. (4)+2476 kJ
  5. 65.
    The surface temperature of the sun which has maximum energy emission at is . The temperature of a star which has maximum energy emission at will be
    1. (1)
    2. (2)
    3. (3)
    4. (4).
  6. 66.
    A sphere, a cube and a thin circular plate all of same material and same mass initially heated to same high temperature are allowed to cool down under similar conditions. Then the
    1. (1)plate will cool the fastest and sphere the slowest
    2. (2)cube will cool the fastest and plate the slowest
    3. (3)plate will cool the fastest and cube the slowest
    4. (4)sphere will cool the fastest and cube the slowest.
  7. 67.
    A 100 g of iron nail is hit by a 1.5 kg hammer striking at a velocity of 60 . What will be the rise in the temperature of the nail if one fourth of energy of the hammer goes into heating the nail? [Specific heat capacity of iron = 0.42 °]
    1. (1)675°C
    2. (2)1600°C
    3. (3)16.07°C
    4. (4)6.75°C
  8. 68.
    Two liquids and have and as contact angles in a capillary tube. If , then identify the correct statement:
    1. (1)K is negative, then liquid A and liquid B have convex meniscus.
    2. (2) is negative, then liquid and liquid have concave meniscus.
    3. (3)K is zero, then liquid A has convex meniscus and liquid has concave meniscus.
    4. (4)K is negative, then liquid A has concave meniscus and liquid has convex
  9. 69.
    Two spherical bodies of same materials having radii 0.2 m and 0.8 m are placed in same
    atmosphere. The temperature of the smaller body is 800 K and temperature of the bigger body is 400 K. If the energy radiated from the smaller body is E, the energy radiated from the bigger body is (assume, effect of the surrounding temperature to be negligible),
    1. (1)16 E
    2. (2)E
    3. (3)64 E
    4. (4)256 E
  10. 70.
    Two uniform brass rods and of length ' ' and ' and their radii ' ' and ' ' respectively are heated to same temperature. The ratio of the increase in the volume of to that of is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  11. 71.
    The quantities of heat required to raise the temperatures of two copper spheres of radii and through are in the ratio of
    1. (1)
    2. (2)
    3. (3)
    4. (4)1
  12. 72.
    Hot water cools from to in the first 10 minutes and to in the next 10 minutes. Then the temperature of the surroundings is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  13. 73.
    A hot body is allowed to cool. The surrounding temperature is constant at . The body takes time to cool from to and time to cool from to . Then,
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  14. 74.
    If the cold junction of a thermo-couple is kept at and the hot junction is kept at , then the relation between neutral temperature () and temperature of inversion () is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  15. 75.
    Two water drops each of radius ' ' coalesce to form a bigger drop. If ' ' is the surface tension, the surface energy released in this process is:
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  16. 76.
    moles of an ideal gas with constant volume heat capacity undergo an isobaric expansion by certain volume. The ratio of the work done in the process, to the heat supplied is:
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  17. 77.
    A sphere, a cube and a thin circular plate all made of same material and having the same mass are heated to same temperature of . When these are left in a room
    1. (1)the sphere reaches room temperature fast.
    2. (2)the cube reaches room temperature fast.
    3. (3)the circular plate reaches room temperature fast.
    4. (4)all will reach the room temperature simultaneously.
  18. 78.
    of water at is mixed with of water at . The final temperature of the mixture is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  19. 79.
    An electric bulb is rated as 200 W. What will be the peak magnetic field at 4 m distance produced by the radiations coming from this bulb? Consider this bulb as a point source with 3.5% efficiency.
    1. (1)1.19 x T
    2. (2)1.71 x T
    3. (3)0.84 x T
    4. (4)3.36 x T
  20. 80.
    A body cools in 7 minutes from 60°C to 40°C. The temperature of the surrounding is 10°C. The temperature of the body after the next 7 minutes will be
    1. (1)30°C
    2. (2)32 C
    3. (3)34°C
    4. (4)28°C
  21. 81.
    Two stars and radiate maximum energy at the wavelengths of and respectively. Then the ratio of the surface temperatures of and is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  22. 82.
    One mole of an ideal gas passes through a process where pressure and volume obey the relation Here and are constants. Calculate the charge in the temperature of the gas if its volume changes from to
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  23. 83.
    The resistances of the platinum wire of a platinum resistance thermometer at the ice point and steam point are and respectively. After inserting in a hot bath of temperature , the resistance of platinum wire is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  24. 84.
    One kg of water, at 20° C, is heated in an electric kettle whose heating element has a mean (temperature averaged) resistance of 20 Ω. The rms voltage in the mains is 200 V. Ignoring heat loss from the kettle, time taken for water to evaporate fully, is close to:
    [Specific heat of water = 4200 J/(kg °C), Latent heat of water kg]
    1. (1)16 minutes
    2. (2)22 minutes
    3. (3)3 minutes
    4. (4)30 minutes
  25. 85.
    A faulty thermometer reads 5°C in melting ice and 95°C in steam. The correct temperature on absolute scale will be.......... K when the faulty thermometer reads 41°C.
  26. 86.
    A block of ice of mass 120 g at temperature 0°C is put in 300 gm of water at 25°C. The xg of ice melts as the temperature of the water reaches 0°C. The value of x is [Use: Specific heat capacity of water = 4200 , Latent heat of ice = 3.5 x ]
  27. 87.
    A steam engine intakes 50g of steam at 100°C per minute and cools it down to 20°C. If latent heat of vaporization of steam is 540 cal , then the heat rejected by the steam engine per minute is______x cal.
  28. 88.
    A steel rod with and of length 4m and area of cross-section is heated from to without being allowed to extend. The tension produced in the rod is where the value of is.......
  29. 89.
    In an insulated vessel, 0.05 kg steam at 373 K and 0.45 kg of ice at 253 K are mixed. Find the final temperature of the mixture (in Kelvin).
    Given, = 80 cal/gm = 336 J/gm, = 540 cal/gm = 2268 J/gm, = 2100 J/kg K = 0.5 cal/gm K and = 4200 J/kg K = 1 cal/gmK
  30. 90.
    A sample of a liquid is kept at 1 atm. It is compressed to 5 atm which leads to a change of volume of . If the bulk modulus of the liquid is 2 GPa, the initial volume of the liquid was _______ liter. (Take )