Physics - Study Mode

[#1291] For an ideal gas, which one of the following statements does not hold true?
Correct Answer

(A) The speed of all gas molecules is same

Explanation

Solution: "The speed of all gas molecules is same" is not a true statement.

[#1292] Due to temperature variation along a conductor, potential variation occurs along it. This phenomenon is known as
Correct Answer

(A) Thomson effect

Explanation

Solution: Due to temperature variation along a conductor, potential variation occurs along it. This phenomenon is known as Thomson effect.

[#1293] The transport phenomenon occurs only in ________ state of a gas and is ________
Correct Answer

(C) Equilibrium, irreversible

Explanation

Solution: The transport phenomenon occurs only in equilibrium state of a gas and is irreversible.

[#1294] What is the reason for twinkling of stars ?
Correct Answer

(D) Atmospheric refraction

Explanation

Solution: Atmospheric refraction is the reason behind the twinkling of stars.
The starlight on entering earth surface undergoes refraction continuously before it reaches to earth. The starlight bend towards the normal as it enters from rarer to denser medium. The air near the earth surface is denser than upper layers. Therefore the apparent position of the stars are slightly different from its actual position, when it is viewed from horizon.
The apparent position of stars are not stationary and keeps on changing slightly, because the physical condition of the atmosphere are not stationary.
Because of this the stars sometimes appears brighter and sometimes appear fainter.

[#1295] The basic reason for the extraordinary sparkle of suitably cut diamond is that
Correct Answer

(C) It has a very high refractive index

Explanation

Solution: The basic reason for the extraordinary sparkle of suitably cut diamond is that it has a very high refractive index.