Tag: physics

Questions Related to physics

State whether the given statement is true or false :

Looking at a solar eclipse without any protective eyewear can severely harm your eyes. 

physics effects of light eclipses elementary ideas of astronomy shadow formation and optical medium

  1. True

  2. False

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Correct Option: A
Explanation:

Looking at a solar eclipse without any protective eyewear can severely harm your eyes. It is safe to look at the Sun during the total solar eclipse since Moon cover the Sun totally. However, it is not safe to look at the Sun during solar eclipse, other than the total solar eclipse.

What is solar eclipse?

physics effects of light eclipses elementary ideas of astronomy shadow formation and optical medium

  1. When Earth, Moon and Sun form a straight line

  2. When Earth, Moon and Sun form a Cross line

  3. When Earth, Moon form a straight line

  4. None

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Correct Option: A
Explanation:

Solar eclipse is the event where the light form the Sun is blocked by the Moon, when Moon passes between the Sun and the Earth and all three forms a straight line.

During partial lunar eclipse, the Moon is in the _______ partially.

physics effects of light eclipses elementary ideas of astronomy shadow formation and optical medium

  1. penumbra core

  2. umbra core

  3. neither A nor B

  4. both A and B

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Correct Option: D
Explanation:

During partial lunar eclipse, moon is in the penumbra core partially and rest is in the umbra core.

Lunar eclipse is very less common phenominon.

Why should you not see the solar eclipse directly?

physics effects of light eclipses elementary ideas of astronomy shadow formation and optical medium

  1. Sun rays are very strong and may cause damage to eyes

  2. Sun rays are weak and may cause strain on your eyes

  3. Sun rays are very strong and may cause a burn on skin.

  4. Sunlight refracts in eclipse and intensity is increased

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Correct Option: A
Explanation:

Direct rays of sun are very strong. 

Looking at it directly may cause severe damage to eyes because of high intensity.

When does total solar eclipse occur?                     

physics effects of light eclipses elementary ideas of astronomy shadow formation and optical medium

  1. When Moon completely covers Sun as seen from earth

  2. When Sun completely covers Moon as seen from earth

  3. When Earth completely covers Sun as seen from moon

  4. None

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Correct Option: A
Explanation:

Total solar eclipse occurs when the Moon is between the Sun and the Earth, and an umbra is cast by the Moon on the Earth's surface.

Which eclipse is known as when Earth's umbra-central dark part shadow obscures all of Moon's visible surface?

physics effects of light eclipses elementary ideas of astronomy shadow formation and optical medium

  1. Hybrid

  2. Total

  3. Partial

  4. Penumbral

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Correct Option: B
Explanation:

Earth cast a shadow on the Moon in a lunar eclipse. Earth's shadow are of 2 types: umbra and penumbra. The darkest or the total shadow is the umbra while the partial shadow is the penumbra. Total eclipse occurs when the Moon is the umbra region.

When does lunar eclipse occurs?

physics effects of light eclipses elementary ideas of astronomy shadow formation and optical medium

  1. When Earth comes between Sun and moon

  2. When Sun comes between Earth and moon

  3. When Moon comes between Sun and Earth

  4. When Earth comes between Star and moon

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Correct Option: A
Explanation:

Lunar eclipse occurs when Moon pass from the behind the Earth or when Earth is betwen the Sun and the Moon. Earth blocks the light of the Sun that would have fallen on the Moon.


State whether the given statement is True or False :

A partial lunar eclipse can be observed when only part of the Moon's visible surface is obscured by the Earth's umbra. 

physics effects of light eclipses elementary ideas of astronomy shadow formation and optical medium

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Earth cast a shadow on the Moon in a lunar eclipse. Earth's shadow are of 2 types: umbra and penumbra. The darkest or the total shadow is the umbra while the partial shadow is the penumbra. Partial lunar eclipse occurs when a part of the Moon is in the umbra region.

Fill in the blank:

Lunar eclipse is a _______ phenomenon.

physics effects of light eclipses elementary ideas of astronomy shadow formation and optical medium

  1. common

  2. less common

  3. impossible

  4. regular

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Correct Option: B
Explanation:

A lunar eclipse occurs when the Moon passes directly behind the Earth into its umbra (shadow). This can occur only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, a lunar eclipse can only occur the night of a full moon. The type and length of an eclipse depend upon the Moon's location relative to its orbital nodes.
Unlike a solar eclipse, which can only be viewed from a certain relatively small area of the world, a lunar eclipse may be viewed from anywhere on the night side of the Earth. A lunar eclipse lasts for a few hours, whereas a total solar eclipse lasts for only a few minutes at any given place, due to the smaller size of the Moon's shadow. 
Every year, there are at least two lunar eclipses and as many as five, although total lunar eclipses are significantly less common. 

The lunar eclipse is generally :  

physics effects of light eclipses elementary ideas of astronomy shadow formation and optical medium

  1. partial

  2. total

  3. either (a) or (b)

  4. cannot say

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Correct Option: B