Explore topic-wise MCQs in Heat Transfer.

This section includes 16 Mcqs, each offering curated multiple-choice questions to sharpen your Heat Transfer knowledge and support exam preparation. Choose a topic below to get started.

1.

The energy radiated out decreases with increases in α and becomes zero at an angle of

A. 45
B. 30
C. 0
D. 90
Answer» E.
Discussion
2.

A black body of 0.2 m2 area has an effective temperature of 800 K. Calculate the intensity of normal radiations

A. 1234.65 W/m2 sr
B. 7396.28 W/m2 sr
C. 3476.74 W/m2 sr
D. 8739.43 W/m2 sr
Answer» C. 3476.74 W/m2 sr
Discussion
3.

The total emissive power of the emitter with area d A and temperature T is given by

A. E = 2 σ T 4 d A
B. E = 3 σ T 4 d A
C. E = σ T 4 d A
D. E = ½ σ T 4 d A
Answer» D. E = ½ σ T 4 d A
Discussion
4.

Consider a deep-space probe constructed as 1 m diameter polished aluminum sphere. Estimate the equilibrium temperature that the probe reaches if the solar energy received is 300 W/m2. For solar radiation, absorptivity of aluminum is 0.3 and the average emissivity appropriate for aluminum at low temperature is 0.04

A. 415.67 K
B. 315.67 K
C. 215.67 K
D. 115.67 K
Answer» C. 215.67 K
Discussion
5.

A small surface emits diffusively, and measurements indicate that the total intensity associated with emission in the normal direction I n = 6500 W/square m sr. The emitted radiation is intercepted by three surfaces. Mark calculations for intensity associated with emission

A. 3500 W/m2 sr
B. 4500 W/m2 sr
C. 5500 W/m2 sr
D. 6500 W/m2 sr
Answer» E.
Discussion
6.

The intensity of normal radiation I n is how much times the emissive power?

A. 1/π
B. 2/ π
C. 3/ π
D. 4/ π
Answer» B. 2/ π
Discussion
7.

If I n denotes the normal intensity and I α represents the intensity at angle α, then

A. I α = 2 I n cos α
B. I α = 3 I n cos α
C. I α = 4 I n cos α
D. I α = I n cos α
Answer» E.
Discussion
8.

A_BLACK_BODY_OF_0.2_M2_AREA_HAS_AN_EFFECTIVE_TEMPERATURE_OF_800_K._CALCULATE_THE_INTENSITY_OF_NORMAL_RADIATIONS?$

A. 1234.65 W/m<sup>2</sup> sr
B. 7396.28 W/m<sup>2</sup> sr
C. 3476.74 W/m<sup>2</sup> sr
D. 8739.43 W/m<sup>2</sup> sr
Answer» C. 3476.74 W/m<sup>2</sup> sr
Discussion
9.

The_energy_radiated_out_decreases_with_increases_in_α_and_becomes_zero_at_an_angle_of$#

A. 45
B. 30
C. 0
D. 90
Answer» E.
Discussion
10.

The total emissive power of the emitter with area d A and temperature T is given b?

A. E = 2 σ T<sup> 4</sup> d A
B. E = 3 σ T<sup> 4</sup> d A
C. E = σ T<sup> 4</sup> d A
D. E = ½ σ T<sup> 4</sup> d A
Answer» D. E = ¬¨¬®≈í¬© ‚âà√¨‚àö√¢ T<sup> 4</sup> d A
Discussion
11.

Consider a deep-space probe constructed as 1 m diameter polished aluminum sphere. Estimate the equilibrium temperature that the probe reaches if the solar energy received is 300 W/m2. For solar radiation, absorptivity of aluminum is 0.3 and the average emissivity appropriate for aluminum at low temperature is 0.04

A. 415.67 K
B. 315.67 K
C. 215.67 K
D. 115.67 K
Answer» C. 215.67 K
Discussion
12.

The intensity of normal radiation I n is how much times the emissive power?

A. 1/π
B. 2/ π
C. 3/ π
D. 4/ π
Answer» B. 2/ ‚âà√¨‚àö√ë
Discussion
13.

If I n denotes the normal intensity and I α represents the intensity at angle α, then$

A. I <sub>α </sub>= 2 I <sub>n</sub> cos α
B. I <sub>α </sub>= 3 I <sub>n</sub> cos α
C. I <sub>α </sub>= 4 I <sub>n</sub> cos α
D. I <sub>α </sub>= I <sub>n</sub> cos α
Answer» E.
Discussion
14.

When the incident surface is a sphere, the projection of surface normal to the line of propagation is the silhouette disk of the sphere which is a circle of the diameter of

A. Parabola
B. Sphere
C. Triangle
D. Hyperbola
Answer» C. Triangle
Discussion
15.

The plane angle is defined by a region by the rays of a circle, and is measured as

A. 3 L/ r
B. 2 L/ r
C. L/ r
D. 4 L / r
Answer» D. 4 L / r
Discussion
16.

The solid angle is defined by a region by the rays of a sphere, and is measured as

A. A<sub>n</sub>/r <sup>2</sup>
B. A<sub>n</sub>/r
C. A<sub>n</sub>/r <sup>3</sup>
D. A<sub>n</sub>/r <sup>4</sup>
Answer» B. A<sub>n</sub>/r
Discussion