Answer:
d). It is easier to make a large reflecting telescope than a large refracting telescope.
f). A reflector can collect more light than a refractor.
Explanation:
A telescope is a device that is used to observe distant objects by the use of lenses and mirrors. It is also used to observe different distant objects by their reflection, absorption, emission or the reflection of the electromagnetic radiations.
Most of the professional telescopes are reflectors because :
1. The reflected telescope is able to receive more of the light when it reflects all the light falling on surface. And it is easier for making a large telescope rather then making large lenses for the refracting telescope. So it is easier to make large reflecting telescope than a large refracting telescope.
2. A reflected telescope receives all the wavelength of the light and it reflects all the light falling on the surfaces where it is refracted telescope that contains lenses cannot absorbs all the light and causes the chromatic aberration.
Answer:
The hydrogen gas is prepared in the laboratory required zink granules, dilute sulphuric acid or dilute hydrogen chloride, flask or woulfe’s bottle, and thistle funnel. by the downward displacement of water because it is a gas lighter than water
Reaction:
Zn (s)+2HCl (aq) →ZnCl2(aq)+H2(g)
Zn (s)+H2SO4(aq)→ZnSO4(aq)+H2(g)
The zinc granules are taken in a flask or Woulfe’s bottle and It is connected with the delivery tube to a water trough containing water. Dilute sulphuric acid is poured slowly from the thistle funnel. The hydrogen gas is released and collected in a gas jar by by the downward displacement of water as H2 gas lighter than water
Answer:
Option (4)
Explanation:
The radiation are defined as the energy that is liberated from atoms in the form of electromagnetic waves or minute particles of matter. For example, the radiations that are emitted from the sun in the form of light.
This radiations are mainly of 3 types. This includes-
(a) Alpha Radiation- These are the short ranged particles and are very heavy. This radiations cannot penetrate the human skins but they can cause harmful diseases.
(b) Beta Radiation- These are also the short-ranged particles but they lighter. This radiations can penetrate the human skin upto the depth where the new skins are created.
(c) Gamma Radiation- These are highly dangerous and are penetrable to the human skin. This type of radiations are often used for the medical purposes.
Thus, the correct answer is option (4).
