Heat Transfer From Extended Surfaces MCQs

Welcome to our comprehensive collection of Multiple Choice Questions (MCQs) on Heat Transfer From Extended Surfaces, a fundamental topic in the field of Heat Transfer. Whether you're preparing for competitive exams, honing your problem-solving skills, or simply looking to enhance your abilities in this field, our Heat Transfer From Extended Surfaces MCQs are designed to help you grasp the core concepts and excel in solving problems.

In this section, you'll find a wide range of Heat Transfer From Extended Surfaces mcq questions that explore various aspects of Heat Transfer From Extended Surfaces problems. Each MCQ is crafted to challenge your understanding of Heat Transfer From Extended Surfaces principles, enabling you to refine your problem-solving techniques. Whether you're a student aiming to ace Heat Transfer tests, a job seeker preparing for interviews, or someone simply interested in sharpening their skills, our Heat Transfer From Extended Surfaces MCQs are your pathway to success in mastering this essential Heat Transfer topic.

Note: Each of the following question comes with multiple answer choices. Select the most appropriate option and test your understanding of Heat Transfer From Extended Surfaces. You can click on an option to test your knowledge before viewing the solution for a MCQ. Happy learning!

So, are you ready to put your Heat Transfer From Extended Surfaces knowledge to the test? Let's get started with our carefully curated MCQs!

Heat Transfer From Extended Surfaces MCQs | Page 6 of 8

Discover more Topics under Heat Transfer

Q51.
In convection from the tip what is the value of correction length?

a.

L C = A C/P

b.

L C = L + A C

c.

L C = L + P

d.

L C = L + A C/P

Discuss
Answer: (d).L C = L + A C/P
Q52.
Let us assume there are two pieces of copper wire 0.1625 cm in diameter with a device that melts it at 195 degree Celsius. The wires are positioned vertically in air at 24 degree Celsius and the heat transfer coefficient of the wire is 17 W/ square m K. Let us say k = 335W/m K i.e. of wire. Find out the energy input?

a.

1.234W

b.

2.652W

c.

4.562W

d.

9.435W

Discuss
Answer: (b).2.652W
Q53.
The figure shows a 5 cm diameter rod, 90 cm long, which is having its lower face grinded smooth. The remainder of the rod is exposed to 32 degree Celsius room air and a surface coefficient heat transfer equal to 6.8 W/m² degree exists between the rod surface and the room air. The grinder dissipates mechanical energy at the rate of 35 W. If thermal conductivity of rod material is 41.5 W/m degree, find the temperature of the rod at the point where the grinding is taking place

a.

161.45 degree celsius

b.

151.45 degree celsius

c.

141.45 degree celsius

d.

131.45 degree celsius

Discuss
Answer: (b).151.45 degree celsius
Q54.
“Effectiveness of fin is the ratio of the fin heat dissipation with fin to that of no fin”. Choose the correct answer

a.

True

b.

False

c.

May be

d.

Can't say

Discuss
Answer: (a).True
Q55.
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

a.

1/ml

b.

2/ml

c.

Aluminum fin

d.

4/ml

Discuss
Answer: (c).Aluminum fin
Q56.
Two long rods A and B of the same diameter have thermal conductivities k and 4k and have one of their end inserted into a furnace at 400 K. At 9.5 m away section from the furnace, the temperature of rod B is120 degree Celsius. So find out at what end from the furnace end, the same temperature would be reached in the rod A?

a.

0.25 m

b.

0.75 m

c.

0.15 m

d.

0.50 m

Discuss
Answer: (a).0.25 m
Q57.
The following factors need consideration for the optimum design of fins

(i) Cost

(ii) Space considerations

(iii) Weight considerations

Choose the correct option

a.

1 only

b.

1 and 2 only

c.

1, 2 and 3

d.

2 only

Discuss
Answer: (c).1, 2 and 3
Q58.
A heating unit is made in the form of a vertical tube of 50 mm outside diameter and 1.2 m height. The tube is fitted with 20 steel fins of rectangular section with height 40 mm and thickness 2.5 mm. The temperature at the base of fin is 75 degree Celsius, the surrounding air temperature is 20 degree Celsius and the heat transfer coefficient between the fin as well as the tube surface and the surrounding air is 9.5 W/m² K. If thermal conductivity of the fin material is 55 W/m K, find the amount of heat transferred from the tube with fin

a.

1234 .98 W

b.

1004.84 W

c.

6539.83 W

d.

3829.46 W

Discuss
Answer: (b).1004.84 W
Q59.
The fins would be effective for heat conduction if the ratio P k/h A C is

a.

Greater than 5

b.

Less than 5

c.

Equal to 5

d.

Varies between 2 to 9

Discuss
Answer: (a).Greater than 5
Q60.
Consider the following statements pertaining to heat transfer through fins

(i) They must be arranged at right angles to the direction of flow of working fluid

(ii) The temperature along the fin is variable and accordingly heat transfer rate varies along the fin elements

(iii) Fins are equally effective irrespective whether they are on the hot side or cold side of the fluid

(iv) Fins are made of materials that have thermal conductivity higher than that of wall

Identify the correct statements

a.

3 and 4

b.

1 and 3

c.

2 and 3

d.

1 and 2

Discuss
Answer: (d).1 and 2
Page 6 of 8