# Thermal Stress MCQ Questions & Answers

Thermal Stress MCQs : This section focuses on the "Thermal Stress". These Multiple Choice Questions (MCQs) should be practiced to improve the Thermal Stress skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.

Question 1

A cube having each side of length p, is constrained in all directions and is heated unigormly so that the temperature is raised to T.C. What will be the stress developed in the cube?

A. Î´ET / Î³
B. Î´TE / (1 - 2Î³)
C. Î´TE / 2
D. Î´TE / (1 + 2Î³)

Question 2

A cube with a side length of 1m is heated uniformly a degree celcius above the room temperature and all the sides are free to expand. What will be the increase in the volume of the cube? Consider the coefficient of thermal expansion as unity.

A. Zero
B. 1 m3
C. 2 m3
D. 3 m3

Question 3

A steel bar 600mm long and having 30mm diameter, is turned down to 25mm diameter for one fourth of its length. It is heated at 30 C above room temperature, clamped at both ends and then allowed to cool to room temperature. If the distance between the clamps is unchanged, the maximum stress in the bar ( Î± = 12.5 x 10-6 per C and E = 200 GN/m2) is

A. 25 MN/m2
B. 40 MN/m2
C. 50 MN/m2
D. 75 MN/m2

Question 4

A steel rod is heated from 25 to 250 degree celcius. Its coefficient of thermal expansion is 10-5 and E = 100 GN/m2. if the rod is free to expand, the thermal stress developed in it is:

A. 100 kN/m2
B. 240 kN/m2
C. Zero
D. Infinity

Question 5

A steel rod of length L and diameter D, fixed at both ends, is uniformly heated to a temperature rise of Î´T. The Youngs modulus is E and the coefficient of linear expansion is unity. The thermal stress in the rod is ____________

A. Zero
B. T
C. EÎ´T
D. EÎ´TL

Question 6

A uniform, slender cylindrical rod is made of a homogeneous and isotropic material. The rod rests on a frictionless surface. The rod is heated uniformly. If the radial and longitudinal thermal stress are represented by Ïx and Ïz, then ___________

A. Ïx = 0, Ïy = 0
B. Ïx not equal to 0, Ïy = 0
C. Ïx = 0, Ïy not equal to 0
D. Ïx not equal to 0, Ïy not equal to 0

Question 7

The length, coefficient of thermal expansion and Youngs modulus of bar A are twice of bar B. If the temperature of both bars is increased by the same amount while preventing any expansion, then the ratio of stress developed in bar A to that in bar B will be ___________

A. 2
B. 4
C. 8
D. 16

Question 8

The length, Young's modulus and coefficient of thermal expansion of bar P are twice that of bar Q. what will be the ration of stress developed in bar P to that in bar Q if the temperature of both bars is increased by the same amount?

A. 2
B. 8
C. 4
D. 16

Question 9

which one of the following are true for the thermal expansion coefficient?

A. Î±aluminium > Î±brass> Î±copper > Î±steel
B. Î±brass > Î±aluminium > Î±copper > Î±steel
C. Î±copper > Î±steel > Î±aluminium > Î±brass
D. Î±steel > Î±aluminium > Î±brass > Î±copper

Question 10

Which one of the following pairs is NOT correctly matched?

A. Temperature strain with permitted expansion - ( Î±Tl - Î´)
B. Temperature thrust - ( Î±TE)
C. Temperature stress - (Î±TEA)
D. Temperature stress with permitted expansion - E(Î±Tl - Î´) / l

Question 11

A steel bar 600mm long and having 30mm diameter, is turned down to 25mm diameter for one fourth of its length. It is heated at 30 C above room temperature, clamped at both ends and then allowed to cool to room temperature. If the distance between the clamps is unchanged, the maximum stress in the bar ( α = 12.5 x 10-6 per C and E = 200 GN/m2) is

A. 25 MN/m2
B. 40 MN/m2
C. 50 MN/m2
D. 75 MN/m2

Question 12

A steel rod of length L and diameter D, fixed at both ends, is uniformly heated to a temperature rise of δT. The Youngs modulus is E and the coefficient of linear expansion is unity. The thermal stress in the rod is ____________

A. Zero
B. T
C. EδT
D. EδTL

Question 13

A uniform, slender cylindrical rod is made of a homogeneous and isotropic material. The rod rests on a frictionless surface. The rod is heated uniformly. If the radial and longitudinal thermal stress are represented by σx and σz, then ___________

A. σx = 0, σy = 0
B. σx not equal to 0, σy = 0
C. σx = 0, σy not equal to 0
D. σx not equal to 0, σy not equal to 0

Question 14

The length, Young’s modulus and coefficient of thermal expansion of bar P are twice that of bar Q. what will be the ration of stress developed in bar P to that in bar Q if the temperature of both bars is increased by the same amount?

A. 2
B. 8
C. 4
D. 16

Question 15

which one of the following are true for the thermal expansion coefficient?

A. αaluminium > αbrass> αcopper > αsteel
B. αbrass > αaluminium > αcopper > αsteel
C. αcopper > αsteel > αaluminium > αbrass
D. αsteel > αaluminium > αbrass > αcopper