Answer:
D
Explanation:
Ball A is a non positively charged non metal while ball B is metal ball.
Given: The ball B positive charge of small magnitude
To prove: Balls will attract each other
IN this condition because of induction negative charges on the sphere B move to the side closer to sphere A,(induction charging) while the positive charges move to the side further away from sphere A. The polarization of charge on B will cause a greater attractive force than the repulsion of the like charges.
Hence the correct answer will be D .
Answer: False
Explanation:
Relative to the concept of radiations, a black body is an object capable of absorbing any form of electromagnetic radiation irrespective of its frequency or angle of incidence when incident on such object.
However, the same cannot be said about real bodies as real bodies are those which reflect all rays incident on them completely and uniformly in all directions.
One very important characteristic of black bodies is that they are ideal emmiters.
The concept of emmisivity is brought about by the existence of real bodies .
This is due to the fact that they are only able to emit radiation at a fraction of the black body energy levels.
Please note that by convention, the emmisivity of a real body is always less thaan 1.
As such they are not able to emit as much radiation as a black body at the same temperature.
The answer is true because A current carrying wire is surrounded by magnetic field
Gravity on the surface = 4 m/s^2
Now, the acceleration due to centripetal motion, a = v^2/R
Where,
v= 10^3 m/s, R = 10^6 m
Then,
a = (10^3)^2/(10^6) = 1 m^2/s
The net gravitational acceleration = 4-1 = 3 m/s^2
The reading on the spring scale = ma = 40*3 = 120 N
Answer:
If you're taking the power of a number with an uncertainty, you multiply the relative uncertainty by the number in the power.
Explanation:
