Physics - Study Mode

[#881] Light beam which is highly directional is called:
Correct Answer

(D) Laser

Explanation

Solution: Light beam which is highly directional is called laser.

[#882] Speed of light is maximum in ________
Correct Answer

(A) Vacuum

Explanation

Solution: Light travels faster in vacuum as compared to any other medium. This is because there is no obstruction in the propagation of light in vacuum as there is no matter in vacuum and also, because the refractive index of vacuum is the lowest i.e. equal to unity.

[#883] Light travels in a straight line (rectilinear propagation of light). This statement does hold if the medium of travel for light is
Correct Answer

(C) Homogeneous and transparent

Explanation

Solution: Light travels in a straight line (rectilinear propagation of light). This statement does hold if the medium of travel for light is homogeneous and transparent.

[#884] The speed of light will be minimum while passing through
Correct Answer

(D) Glass

Explanation

Solution: Light travels at approximately 300,000 kilometers per second in a vacuum, which has a refractive index of 1.0, but it slows down to 225,000 kilometers per second in water and 200,000 kilometers per second in glass.

[#885] The atmospheric air is held to the Earth by :
Correct Answer

(A) Gravity

Explanation

Solution: Surface gravity, the force that holds down an atmosphere, differs significantly among the planets.