Mechanical Engineering Exam  >  Mechanical Engineering Questions  >  Two spheres A and B of same material have rad... Start Learning for Free
Two spheres A and B of same material have radii 1m and 4m and temperature 1000 K and 2000 K respectively. Which one of the following statement is correct.
The energy radiated by sphere A is
  • a)
    greater than that of spheres B
  • b)
    less than that of sphere B
  • c)
    equal to that of sphere B
  • d)
    equal to double that of sphere B
Correct answer is option 'C'. Can you explain this answer?
Verified Answer
Two spheres A and B of same material have radii 1m and 4m and temperat...
View all questions of this test
Most Upvoted Answer
Two spheres A and B of same material have radii 1m and 4m and temperat...
Energy radiated by a sphere

The energy radiated by a sphere can be calculated using the Stefan-Boltzmann law, which states that the power radiated per unit area by a black body is proportional to the fourth power of its absolute temperature. Mathematically, it can be expressed as:

E = εσAT^4

Where:
E is the energy radiated
ε is the emissivity of the material (assumed to be 1 for simplicity in this case)
σ is the Stefan-Boltzmann constant (5.67 x 10^-8 W/m^2K^4)
A is the surface area of the sphere
T is the absolute temperature of the sphere

Therefore, the energy radiated by a sphere is directly proportional to the surface area and the fourth power of the temperature.

Comparison between sphere A and B

1. Surface area:
The surface area of a sphere is given by the formula 4πr^2, where r is the radius of the sphere.

- Sphere A: Surface area = 4π(1)^2 = 4π
- Sphere B: Surface area = 4π(4)^2 = 64π

2. Temperature:
- Sphere A: T = 1000 K
- Sphere B: T = 2000 K

Calculating the energy radiated

Using the formula for energy radiated, we can calculate the energy radiated by each sphere.

- Sphere A: E_A = εσA_T^4 = 1 * 5.67 x 10^-8 * 4π * (1000)^4
- Sphere B: E_B = εσA_T^4 = 1 * 5.67 x 10^-8 * 64π * (2000)^4

Simplifying the equations:

- Sphere A: E_A = 4.52 x 10^11π
- Sphere B: E_B = 1.15 x 10^16π

Comparison of energy radiated

As we can see, the energy radiated by sphere A is approximately 4.52 x 10^11π, while the energy radiated by sphere B is approximately 1.15 x 10^16π.

Since the value of π is constant, we can compare the two energies directly.

- Sphere A: E_A ≈ 4.52 x 10^11
- Sphere B: E_B ≈ 1.15 x 10^16

Therefore, it is clear that the energy radiated by sphere A is much less than that of sphere B. Hence, option 'C' is correct, and the energy radiated by sphere A is equal to that of sphere B.
Attention Mechanical Engineering Students!
To make sure you are not studying endlessly, EduRev has designed Mechanical Engineering study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Mechanical Engineering.
Explore Courses for Mechanical Engineering exam

Similar Mechanical Engineering Doubts

Top Courses for Mechanical Engineering

Two spheres A and B of same material have radii 1m and 4m and temperature 1000 K and 2000 K respectively. Which one of the following statement is correct.The energy radiated by sphere A isa)greater than that of spheres Bb)less than that of sphere Bc)equal to that of sphere Bd)equal to double that of sphere BCorrect answer is option 'C'. Can you explain this answer?
Question Description
Two spheres A and B of same material have radii 1m and 4m and temperature 1000 K and 2000 K respectively. Which one of the following statement is correct.The energy radiated by sphere A isa)greater than that of spheres Bb)less than that of sphere Bc)equal to that of sphere Bd)equal to double that of sphere BCorrect answer is option 'C'. Can you explain this answer? for Mechanical Engineering 2024 is part of Mechanical Engineering preparation. The Question and answers have been prepared according to the Mechanical Engineering exam syllabus. Information about Two spheres A and B of same material have radii 1m and 4m and temperature 1000 K and 2000 K respectively. Which one of the following statement is correct.The energy radiated by sphere A isa)greater than that of spheres Bb)less than that of sphere Bc)equal to that of sphere Bd)equal to double that of sphere BCorrect answer is option 'C'. Can you explain this answer? covers all topics & solutions for Mechanical Engineering 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Two spheres A and B of same material have radii 1m and 4m and temperature 1000 K and 2000 K respectively. Which one of the following statement is correct.The energy radiated by sphere A isa)greater than that of spheres Bb)less than that of sphere Bc)equal to that of sphere Bd)equal to double that of sphere BCorrect answer is option 'C'. Can you explain this answer?.
Solutions for Two spheres A and B of same material have radii 1m and 4m and temperature 1000 K and 2000 K respectively. Which one of the following statement is correct.The energy radiated by sphere A isa)greater than that of spheres Bb)less than that of sphere Bc)equal to that of sphere Bd)equal to double that of sphere BCorrect answer is option 'C'. Can you explain this answer? in English & in Hindi are available as part of our courses for Mechanical Engineering. Download more important topics, notes, lectures and mock test series for Mechanical Engineering Exam by signing up for free.
Here you can find the meaning of Two spheres A and B of same material have radii 1m and 4m and temperature 1000 K and 2000 K respectively. Which one of the following statement is correct.The energy radiated by sphere A isa)greater than that of spheres Bb)less than that of sphere Bc)equal to that of sphere Bd)equal to double that of sphere BCorrect answer is option 'C'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of Two spheres A and B of same material have radii 1m and 4m and temperature 1000 K and 2000 K respectively. Which one of the following statement is correct.The energy radiated by sphere A isa)greater than that of spheres Bb)less than that of sphere Bc)equal to that of sphere Bd)equal to double that of sphere BCorrect answer is option 'C'. Can you explain this answer?, a detailed solution for Two spheres A and B of same material have radii 1m and 4m and temperature 1000 K and 2000 K respectively. Which one of the following statement is correct.The energy radiated by sphere A isa)greater than that of spheres Bb)less than that of sphere Bc)equal to that of sphere Bd)equal to double that of sphere BCorrect answer is option 'C'. Can you explain this answer? has been provided alongside types of Two spheres A and B of same material have radii 1m and 4m and temperature 1000 K and 2000 K respectively. Which one of the following statement is correct.The energy radiated by sphere A isa)greater than that of spheres Bb)less than that of sphere Bc)equal to that of sphere Bd)equal to double that of sphere BCorrect answer is option 'C'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice Two spheres A and B of same material have radii 1m and 4m and temperature 1000 K and 2000 K respectively. Which one of the following statement is correct.The energy radiated by sphere A isa)greater than that of spheres Bb)less than that of sphere Bc)equal to that of sphere Bd)equal to double that of sphere BCorrect answer is option 'C'. Can you explain this answer? tests, examples and also practice Mechanical Engineering tests.
Explore Courses for Mechanical Engineering exam

Top Courses for Mechanical Engineering

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev