MCQOPTIONS
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MCQOPTIONS
This section includes 5 Mcqs, each offering curated multiple-choice questions to sharpen your Physics Questions and Answers knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Two spheres, A & B, are made up of the same material. The radius of A is twice that of B, while the temperature of A is half that of B. What is their ratio of energy emitted per unit time (EA : EB)? |
| A. | 1 |
| B. | 1/4 |
| C. | 1/2 |
| D. | 1/16 |
| Answer» C. 1/2 | |
| 2. |
The sun emits light having maximum intensity at a wavelength 468nm. Assume emissivity of sun is 1. Calculate its surface temperature. σ= 5.67*10-8W/m2K4. |
| A. | 6800K |
| B. | 3400K |
| C. | 6196K |
| D. | 7200K |
| Answer» D. 7200K | |
| 3. |
What is the net amount of energy per unit time being received by a body having a temperature of 40 °C in a surrounding of 60°C? (The surface area of body = 2m2, σ = 5.67*10-8W/ m2K4 & emissivity of 0.4). |
| A. | 122.4W |
| B. | 0.47W |
| C. | 33W |
| D. | 86W |
| Answer» B. 0.47W | |
| 4. |
What is the value of Wien’s constant? |
| A. | 2.9*10-3mK |
| B. | 2.9*10-4mK |
| C. | 2.9*10-3cmK |
| D. | 2.9*10-4cmK |
| Answer» B. 2.9*10-4mK | |
| 5. |
A steel and a copper bar are joined end to end. The area of the steel bar is half the area of the copper bar. Their lengths are equal to 10cm each. Temperature of free ends of steel & copper rod are 0°C & 100°C respectively. KS = 50 J/smK & KC =384 J/smK. Calculate equivalent thermal conductivity of the combined bar. |
| A. | 63°C |
| B. | 63K |
| C. | 336°C |
| D. | 36K |
| Answer» B. 63K | |