Physics - Study Mode
[#846] Solar energy is due to
Correct Answer
(A) Fusion reactions
Explanation
Solution: Solar energy is any type of energy generated by the sun. Solar energy is created by nuclear fusion that takes place in the sun. Fusion occurs when protons of hydrogen atoms violently collide in the sun's core and fuse to create a helium atom.
[#847] Which of the following is optical illusion?
Correct Answer
(D) Mirage
Explanation
Solution: A mirage is a naturally occurring optical illusion or phenomenon in which light rays are bent due to refraction in layers of air of varying density. The image usually is upside down, enhancing the illusion that the sky image seen in the distance is really a water or oil puddle acting as a mirror.
[#848] One can distinguish a telescope from a microscope by observing
Correct Answer
(D) Length and size of the lens
Explanation
Solution: One can distinguish a telescope from a microscope by observing length and size of the lens.
[#849] Electron microscope works on which of the following principles?
Correct Answer
(B) Wave Nature of electrons
Explanation
Solution: Electron microscope works on the principle of Wave Nature of electrons. Electron microscopes use an electron beam instead of visible light and an electron detector instead of our eyes. An electron beam allows us to see at very small scales because electrons can also behave as light due to its wave nature.
[#850] Holography is a technique of
Correct Answer
(D) Recording a permanent three dimensional photograph of a given single colour or a multicolour
Explanation
Solution: Holography is a photographic technique that records the light scattered from an object, and then presents it in a way that appears three-dimensional.