CBSE > Class 08 > Science | CBSE Board | Homework Help

1.When incomplete combustion occurs harmful products -carbon monoxide (and other products which are not harmful)
2.When complete combustion occurs harmful products are-carbon dioxide, (and other products which are not harmful)

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In humans where is the development of fertilised egg takes place?

Posted by Kongalla Vivek 5 years, 8 months ago

CBSE > Class 08 > Science

1 answers

Tiasha Barai 5 years, 8 months ago

In the uterus of the mother

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Explain how does lightning conducted protects a building from getting stuck by lightning?

Posted by Kongalla Vivek 5 years, 8 months ago

CBSE > Class 08 > Science

1 answers

Yogita Ingle 5 years, 8 months ago

i. It is a device used to protect the building from lightning effects.

ii. It is a long metallic rod taller than building installed on the walls of the building.

iii. One end of the rod is kept out in the air and other is buried deep in the ground connected with a copper plate.

iv. The rod provides an easy route for the transfer of electric charge to the ground.

v. That’s how lightning conductor protects a building from getting struck by lightning.

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Explain different things occurs during adolescence in mens

Posted by Vikramjit Singh 5 years, 8 months ago

CBSE > Class 08 > Science

1 answers

Yogita Ingle 5 years, 8 months ago

Humans become capable of reproduction after puberty sets in. Between the ages of 11 years and 19 years children are called adolescents.
The onset of puberty brings about growth of the reproductive organs.
Hair grow at various places on the body. Breasts develop in girls and facial hair (moustache and beard) appear in boys. Voice of boys becomes hoarse as voice box enlarges during adolescence.
?Children gain height during adolescence.

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How much distance can a light from a laser torch can travel ?

Posted by Vikramjit Singh 5 years, 8 months ago

CBSE > Class 08 > Science

1 answers

Rishi Raj 5 years, 8 months ago

It depends on climate

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If two mirrors are kept enclined at an angle 45 degree.what will be the number of images form?????????????? Write the formula...

Posted by Ritu Raz 5 years, 8 months ago

CBSE > Class 08 > Science

4 answers

Tanushri Deshpande 5 years, 8 months ago

7 images As the formula is (360 ÷ angle of incidence minus 1 ) therefore (360 ÷ 45) -1 equals to 8 - 1 = 27

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Krishna Murari Roy 5 years, 8 months ago

Answer is 7 Number of images formed=(360/angle of inclination)-1 =(360/45)-1 =8-1 =7

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Mandaliya Daxesh 5 years, 8 months ago

It will form 7 mirrors If you want to check then use the method N=(360/Q)- 1

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Yogita Ingle 5 years, 8 months ago

Given , an object is placed between two plane mirrors inclined at 45 degree to each other .
let z images expet to see ,
z = {tex} \frac{360 }{45} - 1{/tex} = 8 - 1 = 7
. ' . 7 images are forming .

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Define the construction of kaleidoscope..

Posted by Ritu Raz 5 years, 8 months ago

CBSE > Class 08 > Science

1 answers

Yogita Ingle 5 years, 8 months ago

A kaleidoscope is composed of a hollow tube. Three mirrors are placed in the form of a triangular tube and their reflecting surfaces face each other. One end of the tube is covered with a transparent sheet and another end is covered with an opaque sheet. There is an eyehole in the opaque sheet. Bits of glass are filled inside the tube. When a kaleidoscope is turned, we get to see various patterns in it. These patterns are formed because of multiple reflections

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Hydra reproduce by

Posted by Priyanka Naik 5 years, 8 months ago

CBSE > Class 08 > Science

1 answers

Sssssssssssssss Yyyyyyyyyyyyyyy 5 years, 8 months ago

Hydra reproduce asexually by producing buds .

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Explain mensuration

Posted by Akash Sasidharan 5 years, 8 months ago

CBSE > Class 08 > Science

1 answers

Ritu Raz 5 years, 8 months ago

It is the period of adolescence , in which the reproductive organs are ready to reproduce which causes bleedind in womens.It occures in 28 to 30 days.

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We can prepare tea in paper cup while paper cup and it does not catch fire .explain the process

Posted by Mandaliya Daxesh 5 years, 8 months ago

CBSE > Class 08 > Science

1 answers

Yogita Ingle 5 years, 8 months ago

This is because when we heat the paper cup containing water, then the heat supplied to the paper cup is transferred to water inside it by conduction. Due to continuous transfer of heat from Paper Cup to water , the paper cup does not get heated to its ignition temperature. Hence the paper cup does not catch fire.

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Write function of estrogen hormone in human

Posted by K Raghu 5 years, 8 months ago

CBSE > Class 08 > Science

0 answers

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Is light is fast or sound? Send answer with thier speeds

Posted by Anita Dwivedi 5 years, 8 months ago

CBSE > Class 08 > Science

4 answers

Rishi Raj 5 years, 8 months ago

Light

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Ritu Raz 5 years, 8 months ago

Light is much faster than sound. The speed of light is 300,000,000 m/sec

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N Tarush Tarang 5 years, 8 months ago

Light ?

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Parth Pawar 5 years, 8 months ago

Iight

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Clonning

Posted by Yasoda Parmar 5 years, 8 months ago

CBSE > Class 08 > Science

1 answers

Rishi Raj 5 years, 8 months ago

Making anything like itself

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In pachmarhi biosphere reserve there are different biosphere in it

Posted by Anjali And Aditya Jungade 5 years, 8 months ago

CBSE > Class 08 > Science

1 answers

Meghna Thapar 5 years, 7 months ago

A biosphere reserve may also contain other protected areas in it. For example - a Biosphere Reserve may contain Wildlife Sanctuary or a National Park. The Pachmarhi Biosphere Reserve consists of one national park named Satpura and two wildlife sanctuaries named Bori and Pachmarhi.

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Why venus is the hotest planet

Posted by Agrima Singh 5 years, 8 months ago

CBSE > Class 08 > Science

5 answers

Rishi Raj 5 years, 8 months ago

Because it is too closer to sun

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Krishna Murari Roy 5 years, 8 months ago

Venus is the most hottest planet in our solar system because it's atmosphere is mostly filled with carbon dioxide which prevent it's heat to escape. Therefore making it the hottest planet.

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Yogita Ingle 5 years, 8 months ago

Mercury and Venus are two most closely situated planets from the Sun. Mercury is first to the Sun still Venus is more hot. This is largely due greenhouse effect. Greenhouse effect is a phenomenon in which heat gets trapped by some special category of gases which conduct heat, known as greenhouse gases. When the heat from the Sun strikes the planets atmosphere, the CO2 traps the heat into the atmosphere. Clouds in Venus are made up of sulfur dioxide and droplets of sulphuric acid. They reflect 75% of heat and light, but presence of carbon dioxide absorbs heat and planet remains hot.

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Aastha Gupta 5 years, 8 months ago

A pendulum Australian null 40 times in 4 second find its time period and frequency

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Saurav Negi 5 years, 8 months ago

Bevause suns atmospjere is more hotter than its surface that why

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Wht is effect of change in atmosphere pressure in body

Posted by Raj Kumar Yadav 5 years, 8 months ago

CBSE > Class 08 > Science

1 answers

Saurav Negi 5 years, 8 months ago

High or low blood pressure

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Why sun is red in the evening

Posted by It' Sarang 5 years, 8 months ago

CBSE > Class 08 > Science

2 answers

Yogita Ingle 5 years, 8 months ago

The Sun appears red during sunrise and sunset because the rays from the Sun has to travel a longer distance compared to the noon. Sun rays contain seven colors out of which red color has the highest wavelength. Thus, red colour is not scattered away by the atmosphere and reaches the Earth while other colors like blue etc get scattered way. Thus, the Sun appear reddish.

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Piyush Kumar 5 years, 8 months ago

Because it is angry in evening

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Which is the smallest cell in world

Posted by Atul Khatri 5 years, 8 months ago

CBSE > Class 08 > Science

3 answers

Krishna Murari Roy 5 years, 8 months ago

Mycroplasma

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Anita Dwivedi 5 years, 8 months ago

Mycoplasma is the smallest cell on the world

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Saurav Negi 5 years, 8 months ago

Hiskbosone

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Metamorphosis is also konwn as mensoration cycle

Posted by Kiran Kumari 5 years, 8 months ago

CBSE > Class 08 > Science

1 answers

Suhani Sabat 5 years, 8 months ago

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Write the chemical components of match stick

Posted by Sripoorna Bodha 5 years, 8 months ago

CBSE > Class 08 > Science

1 answers

Meghna Thapar 5 years, 7 months ago

The tip of Match has potassium chlorate (an oxidant), sulfur, starch, glue and some other ingredients. The striking Surface consists of red phosphorus , powdered glass, and glue.When a match strikes on striking surface, the heat of the friction causes a reaction between the potassium chlorate in the match head and the red phosphorus in the striking surface. That way sparks are formed, which finally ignite the match head that continues to burn after that, the friction caused by the glass powder rubbing together produces enough heat to turn a very small amount of the red phosphorus into white phosphorus, which catches fire in air. . The heat and oxygen gas then cause the sulfur to burst into flame, which then catches the wood of the match to catch on fire.

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How is sound produced

Posted by Sandeep Chaudhary 5 years, 8 months ago

CBSE > Class 08 > Science

2 answers

Rishi Raj 5 years, 8 months ago

Sound is produced by vibration

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Yogita Ingle 5 years, 8 months ago

Sound is produced when something vibrates. The vibrating body causes the medium (water, air, etc.) around it to vibrate. Vibrations in the air are called travelling longitudinal waves, which we can hear. Sound waves consist of areas of high and low pressure called compressions and rarefactions, respectively.

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Give names of two methods if reproduction in animals?

Posted by Dharmender Rachan 5 years, 8 months ago

CBSE > Class 08 > Science