Miscellaneous Problems based on Conduction - MCQ - Basic

Miscellaneous Problems based on Conduction - MCQ - Basic Level

Dear Readers,

Physics is an important subject in preparation for various Competitive exams. To keep a track of your preparation we have designed a small quiz of Basic Level Questions on Miscellaneous Problems based on Conduction. You have 10 minutes to solve the quiz, click the start timer button in order to start the timer and then click on submit button at the end to submit the quiz and view your scores and correct answers.

Q1. There are two identical vessels filled with equal amounts of ice. The vessels are of different metals. If the ice melts in the two vessels in 20 and 35 minutes respectively the ratio of the coefficients of thermal conductivity of the two metals is

•  4 : 7
•  7 : 4
•  16 : 49
•  49 : 16

Q2. Temperature at the surface of lake is –20°C. Then temperature of water just below the lower surface of ice layer is

•  -4°C
•  0°C
•  4°C
•  -20°C

Q3. Two identical rods of copper and iron are coated with wax uniformly. When one end of each is kept at temperature of boiling water, the length upto which wax melts are 8.4 cm and 4.2 cm respectively. If thermal conductivity of copper is 0.92, then thermal conductivity of iron is

•  0.23
•  0.46
•  0.115
•  0.69

Q4. During severe winter in the low temperature zones of the world, the superficial parts of the lakes are frozen, leaving water below. The freezing at the bottom is prevented because

•  The conductivity of ice is low
•  The water has large specific heat
•  The water has large latent heat of fusion
•  The temperature of the earth at the bottom of the lake is high

Q5. If the steady thickness of ice layer is 100 cm and that of water is 4.20 m in a lake of a cold country where temperature of air is – 5.0°C and temperature of water at the bottom is 4°C. The ratio of the thermal conductivity of water to that of ice is

•  4 : 3
•  4.25 : 1
•  3 : 1
•  5.25 : 1

Q6. A 10 cm layer of ice has been formed over a pond of water. The temperature of air above is –5°C. How long will it take the layer to become 10.1 cm thick? (Given K_ice = 0.008 CGS units, density of ice = 1 gm/cc and L_ice = 80 cal/gm)

•  2005 sec
•  1705 sec
•  1405 sec
•  705 sec