Heat Transfer Mock Test 3

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Question 1 of 10

1. Which of the following is not correct in a transient flow process?

The rate of inflow and outflow of mass are different

There is no accumulation of energy inside the control volume

The state of matter inside the control volume varies with time

There can be work and heat interactions across the control volume

Question 1 of 10

Question 2 of 10

2. Heat dissipation by every segment of the fin is

Not same

Same

Sometimes same or sometimes not same

Sometimes same

Question 2 of 10

Question 3 of 10

3. Which fin yields the maximum heat flow per unit weight?

Curved triangular fin

Hyperbolic fin

Parabolic fin

Straight triangular fin

Question 3 of 10

Question 4 of 10

4. What percentage of water an average human body can have?

72%

82%

52%

62%

Question 4 of 10

Question 5 of 10

5. Three fins of equal length and diameter but made of aluminum, brass and cast iron is heated to 200 degree Celsius at one end. If the fins dissipate heat to the surrounding air at 25 degree Celsius, the temperature at the free end will be least in

Cast iron fin

Brass fin

Each fin will have the same temperature

Aluminum fin

Question 5 of 10

Question 6 of 10

6. Thermometric well apparatus doesn’t consist of

Ammeter

Thermometer

Pipe line

Oil

Question 6 of 10

Question 7 of 10

7. A rod of 10 mm square section and 160 mm length with thermal conductivity of 50W/m K protrudes from a furnace wall at 200 degree Celsius with convective coefficient 20 W/ square m K. Make calculations for the heat convective up to 80 mm length

6.84W

5.47W

7.34W

4.54W

Question 7 of 10

Question 8 of 10

8. The transient response of a solid can be determined by the equation. (Where, P is density, V is volume, c is specific heat and A is area)

– p V c = h A (t – t₀)

– 3 p V c = h A (t – t₀)

– 2 p V c = h A (t – t₀)

– 4 p V c = h A (t – t₀)

Question 8 of 10

Question 9 of 10

9. The temperature distribution in case of infinitely long fin is

t – t _a/t ₀ – t_a= mx

t – t _a/t ₀ – t_a = -mx

t – t _a/t ₀ – t_a= e^{-m x}

t – t _a/t ₀ – t_a= log (m x)

Question 9 of 10

Question 10 of 10

10. A low value of time constant can be achieved for a thermocouple by
(i) Increasing the wire diameter
(ii) Increasing the value heat transfer coefficient
(iii) Use light metals of low density and low specific heat

i, ii and iii

i and iii

i and ii

ii and iii

Question 10 of 10