Physics - Study Mode

[#376] Where does hydroelectric energy come from?
Correct Answer

(B) Water

Explanation

Solution: Hydroelectric power is produced with moving water.

[#377] Which colour has the highest energy?
Correct Answer

(A) Violet

Explanation

Solution: When it comes to visible light, the highest frequency color, which is violet, also has the most energy.

[#378] Red is used as an emergency or danger signal as
Correct Answer

(B) Its wavelength is the longest

Explanation

Solution: Danger signals are red in color because it is scattered the least by air molecules. Since the color red has the highest wavelength of all the colors we can see it scattered the least. So, red light is used as a danger signal as it is able to travel the longest distance through the fog, rain, etc.

[#379] Which of these travels in glass with minimum velocity ?
Correct Answer

(B) Violet light

Explanation

Solution: As light passes from air into glass, there is reduction of velocity. Due to longer wavelengths, red waves travel fastest and is refracted the least, while violet waves travel the slowest and is refracted the most.

[#380] Which of the following is not a property of heavy water ?
Correct Answer

(A) Boiling point of heavy water is lower than that or ordinary water

Explanation

Solution: Boiling point of heavy water is lower than that or ordinary water is not a property of heavy water.