10th class, Get together off… scientific reasons

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Today we will see the scientific reasons for the question asked in the question paper. Each question has a specific characteristic. Marks are not deducted/subtracted when the answer is written without understanding the characteristics of that question. Our answer should be as per the question weightage. Scientific reason question is asked for 4 marks in the exam of the class 10th and 9th. In the exam, it is asked in Q 2 A, 2 marks each. This means we have to attempt any two out of three questions.

In this format at least one question on chemistry and at least one question on physics. If we write a proper answer in 2 points then we will get one mark each for that point.

If we can give a scientific reason, one can say that we have studied science well enough for that question.

Next are some scientific reasons. Let’s try how many questions can be answered.🎷

 *The camel is called the ship of the desert.

* The water in the earthen pot gets cooled.

*Atom is electrically neutral.

*At dawn, in winter,  we see dew drops on the leaves of grass.

*Earthworm is called a friend of the farmer.

*Carbon dioxide is used for putting out fires.

*A Condenser has two taps.

*All the mass of an atom is concentrated in the nucleus.

* A Magnetic needle is used in a mariner’s compass.

* The danger from the greenhouse effect is rising.

*Solar energy is the source of all forms of energy.

*If a bar magnet is suspended vertically it does not hang in the north-south direction.

*The single-crop method can prove fatal/harmful.

*We only see one side of the moon.

*Deposits of fossil fuels are limited.

*In an electric Bell the electric current stops again and again.

* The proportion of nitrogen in the air remains constant.

* Gold and platinum are called Nobel elements.

*Electrical switches are made of plastic.

*The tiles are placed over a slushy patch of ground to help cross it.

*Diamonds are used to cut metals.

*The planets do not collide with one another.

*Ornaments are generally not made from 24-carat gold.

*Saturn is said to have unique characteristics.

*An ST bus has four rear wheels.

*Biodiversity should be conserved.

 * mitochondria are called the powerhouse of the cell.

*You do not see the image of an object in a mirror if you go behind the mirror to look for it.

* Fungi are called saprophytic.

*We should not use uncovered food.

*Letters appear laterally inverted in a plane mirror.

*Horses are given horse gram as supplementary food.

*The roots of plants sown in well-plugged soil grow stronger and deeper.

*The proportion of nitrogen in the air remains constant.

* Milch animals are fed with ambon or silage.

*The intestines of dead animals can be used.

*Use of too much water and chemicals should be avoided.

The above question number is very less 

 As we learn the Good Book of Science as our intellect increases, more questions come to us.

 It is said that scientists do not have the answers to some questions. 

Now let’s go through some questions of Class 10th, Scientific Reasoning Part. 

🎷 The sun is seen on the horizon a little before sunrise. Or

We see The Sun even before its emergence above The horizon.

(Medium, refraction appears)

Ans:-1. Near the surface of the earth dense atmosphere is present. Light rays from the sun enter the Earth’s atmosphere from outer space, they travel from a rare medium to a denture medium. Hence these light rays bend toward the normal on refraction.

2. Though the Sun is below the horizon while rising or setting its light rays reach us due to refraction, therefore the sun appears to be on the horizon.

So the sun is seen on the horizon a little before sunrise or after sunset.

* . Stars appear to be twinkling at night.

Or

Star  Twinkle but we do not see the twinkling of planets.

(Point source, temperature , refraction, Apparent position, refractive index)

Ans:- 1. For us stars are point sources of light because they are far away from us. The motion, density, and temperature of air continuously change. As a result the refractive index of air in a given region also changes. Hence there is a continuous change in the Apparent position and brightness of a star. The combined effect of all, the star appears to Twinkle.

2. Planets are relatively closer to the earth. So planets appear as a collection of the largest number of point sources. The refractive index of air in a given region changes continuously there is no change in the average Apparent position and brightness of a planet. Hence we do not see the twinkling of the planet.

* . A coin kept in a bowl is not visible when seen from one side. But, when water is poured into the bowl, the coin becomes visible.

(barrier, refraction)

Ans:- 1. In an empty bowl, the rays of light coming from the coin are obstructed. Therefore the coin is not visible when seen from one side.

2. As we added water to the bowl, there were two medium denser water and lighter air. So the light ray bends away from the normal due to refraction.

Therefore A coin kept in a bowl is not visible when seen from one side. But, when water is poured into the bowl, the coin becomes visible.

* A pencil deep in the water obliquely appears bent at the surface of the water.

(Two medium, refraction)

Ans:-1. In deep conditions the rays of light coming from the emerged part of the pencil emerge from water (which means a denser medium ) and enter the air (which means a lighter medium) and inter air means a rare medium.

Due to refraction, the propagation of light rays bent away from the normal.

2. Due to medium changes the immersed part of the pencil does not appear straight concerning the part outside the water, but it appears to be raised.

Hence a pencil deep in the water obliquely appears bent at the surface of the water.

* Watch repairers use a magnifying glass. or

A simple microscope is used for watch repairs.

(Principle, nature of image)

Ans:-1. A convex lens is used to obtain a large and erect image on the same side of a small substance.

2. To see the small parts of the watch, such as the wheels, hands, and screw it is necessary to put the watch within the focal length of a convex lens.

3. By existing the distance between the object and the convex lens, the image can be obtained at the minimum distance of distinct vision.

Hence watch repairers use a magnifying glass to see the minute parts more clearly. 

* When a burning stick of incense is moved fast in a circle, a circle of red light is seen.

(Impression 1/16 sec, persistence of vision )

Ans:- 1. If we see any object, its impression remains on the retina for the 16th of a second.

2. If the burning stick is moved at more than 16 revolutions per second, we (appear) see a circle of red light due to the persistence of vision.

* It is risky to issue a driving license to a person suffering from colour blindness.

(Distinguish colour, accident, conical cells)

Ans:- 1. Some people like conical cells responding to certain colours.

2. This person cannot recognize some colours or cannot distinguish between different colours.

3. A colour blind driver is unable to distinguish the colours of the signal and the colours on different sign boards.

Hence,  It is risky to issue a driving license to a person suffering from colour blindness.

* Colour-blind persons are unable to distinguish between different colours.

(Absence of cone-shaped cells, )

Ans:- 1. The conical cells respond to the colour and give information about the colour of the object to the brain.

2. But in the retina of colour blind persons cone-shaped cells are absent.

Hence Colour-blind persons are unable to distinguish between different colours.

Add new knowledge every day.

 *यश ही तुमची सावली आहे. तिला पकडायचा प्रयत्न करू नका. तुमचा मार्ग चालत रहा, ती आपोआप तुमच्यामागे येईल. लक्षात ठेवा सावली तेंव्हाच तुमच्या मागे येते जेव्हा तुम्ही प्रकाशाच्या दिशेने चालता.*🎷