Physics - Study Mode

[#1281] The reflector of a search light is a :
Correct Answer

(B) Concave mirror

Explanation

Solution: Concave mirrors are used in search lights and torches so that we have a more focused light beam which will not diverge out and hence help in searching. It is used for different light rays falling on it to a single point.

[#1282] Optical Fibre technology works on which of these principles of Physics?
Correct Answer

(C) Total internal reflection of Light

Explanation

Solution: The optical fibre is a device which works on the principle of total internal reflection by which light signals can be transmitted from one place to another with a negligible loss of energy.

[#1283] What is the reason for formation of Mirage in desert?
Correct Answer

(D) Both Refraction and Total internal reflection of light

Explanation

Solution: Mirage is formed due to both Refraction and Total internal reflection of light. A mirage is a naturally occurring optical phenomenon in which light rays bend to produce a displaced image of distant objects or the sky.

[#1284] What factors contribute to global winds?
Correct Answer

(D) All of the above

Explanation

Solution: Global winds are affected by convection current, pressure gradients, the Coriolis effect, and friction.

[#1285] Two metallic plate of equal thickness and coefficient thermal conductivity K1 and K2 put together face to face. A common plate is constructed. What is equivalent K?
Correct Answer

(B) 2k1k2/k1+k2

Explanation

Solution: Equivalent K will be 2k1k2/k1+k2.