Goyal Brothers Prakashan solutions for A New Approach to ICSE Physics [English] Class 10 chapter 5 - Electromagnetic Waves and Spectrum [Latest edition]

Name the unit in which wavelength of electromagnetic waves is measured.

What is the range of wavelengths of visible light?

How does the colour of visible light change as its wavelength gradually decreases?

1. A mixture of red, blue, and green light rays is passed through a convex lens, as illustrated in the diagram below. State whether the ray passes through a single point or through different points on the principal axis after refraction.
   
2. Name the invisible radiation which is studied using the quartz prism.
3. State one use of the radiation mentioned by you in (b) above.
4. Name one type of radiation with a wavelength greater than that of the radiation mentioned by you in (b) above.

Define the term dispersion of light.

Define the following:

Scattering of light

Define the following:

Spectrum

1. By drawing a neat diagram, trace the path of ray of white light, through an equiangular glass prism, till it emerges out of a prism and strikes a white screen.
2. Write the sequence of colours formed on the white screen from bottom upward.
3. What is your observation, if white screen is replaced by a green screen? Give a reason.

Diagrams given below shows two equilateral glass prisms and a ray of white light incident on prism A.

1. Copy the diagram and trace the course of white ray of light, till it strikes the screen.
2. Write about two conclusions which you can draw about the nature of white light.

Which physical quantity determines colour of visible light?

Which colour of visible light deviates least in an optical medium?

Which colour of visible light deviates most in an optical medium?

For which colour the refractive index of an optical medium is maximum?

For which colour the refractive index of an optical medium is minimum?

What name is given to electromagnetic waves beyond red?

What name is given to electromagnetic waves beyond violet?

What do you understand by the invisible spectrum? 

Name four broad electromagnetic wave bands of invisible spectrum, beyond the red band of visible spectrum.

Name four broad electromagnetic wave bands of invisible spectrum, beyond the violet band of visible spectrum.

What are infrared radiations?

What is the range of infrared radiation in Å?

How can you detect infrared radiation? Explain briefly.

State the properties of infrared radiation.

State two uses of infrared radiations.

Does our body emit infrared radiation. If so state their approximate range.

What are ultraviolet radiations?

What is the range of ultraviolet radiation in Å?

How can you detect ultraviolet radiation? Explain briefly.

State the properties of ultraviolet radiation.

State two uses of ultraviolet radiation.

State one harm, the ultraviolet radiation can cause to human body.

How does nature protect us from the harmful effects caused by ultraviolet radiation.

Which optical material absorbs least amount of ultraviolet radiation?

How is ultraviolet radiation useful to human being?

How is ultraviolet radiation useful to jewellers?

How is ultraviolet radiation useful to bankers?

Why does a welder keep a special kind of glass between the object to be welded and his eyes? Explain.

Why is the infrared radiation preferred over visible light for photography in the fog?

Which colour of white light scatters most?

Which colour of white light scatters least?

Why does the sky appear in blue colour?

Why does sky appear black on the surface of moon?

Why does distant hill appear blue on sunny days?

Why does we soak over washed clothes in ultramarine?

Why are yellow or orange head lights used in foggy weather?

Why does smoke from a chimney appear blue, instead of black during winter morning?

Name any two electromagnetic waves which have a frequency higher than that of violet light. State one use of each.

What is Newton’s disc?

What does Colour disc experiment establish about the nature of light.

1. Name the high energetic invisible electro-magnetic wave which helps in the study of structure of crystals.
2. State one more use of the wave named in part (a).

How does the speed of light in glass change on increasing the wavelength of light?

Two parallel rays of red and violet travelling through air meet the air-glass boundary as shown in the diagram. Will their paths inside the glass be parallel? Give a reason for your answer. Compare the speeds of the two rays inside the glass.

Name the radiations that are used for photography at night.

Name the radiations used for the detection of fracture in bones.

Name the radiations whose wavelength range is from 100 Å to 4000 Å (or 10 nm to 400 nm).

Name the material prism required for obtaining the spectrum of ultraviolet light.

Name the radiation which can be detected by a thermopile.

Why is the colour red used as a sign of danger?

Visible light has electromagnetic waves between ______.

1 Angstrom unit (Å) is equal to ______.

The most visible colour of visible spectrum is ______.

The band of seven colours formed, when white light passes through an equilateral prism is called ______.

Violet, green, red and yellow are the four colours formed on a white screen when a polychromatic light is dispersed. The arrangement of colours in the decreasing order of wavelengths is:

The angle of deviation is maximum for ______ when the dispersion of polychromatic light takes place.

Which is not a source of ultraviolet radiations?

The electromagnetic radiation which are useful in night photography is ______.

The electromagnetic wave associated with high energy is ______.

During the Sunset the colour which scatters closest to the eye of observer is:

Infrared rays with very large wavelength are easily reflected by ______.

X-rays are produced by:

The electromagnetic waves which produce heating effect in material bodies are:

The greenhouse effect is caused when ______.

The sensation of colour depends upon the ______.

A wave having a wavelength between 5780 Å and 5000 Å produce a sensation of green. If wavelength is between 5000 Å and 4640 Å, the sensation of colour will be:

When all the seven bands of colour of white light are simultaneously incident on the retina the final perception of colour is:

The sensation produced in the brain when a visible light of some specific wavelength excites retina is called ______.

Colour is a ______.

When the white light enters into a glass prism:

Inside the prism, during the dispersion of white light, compared to blue, red light ______.

The region of spectrum which is invisible and extends beyond red region of visible spectrum consists of:

The region of spectrum which is invisible and extends beyond violet region of visible spectrum consists of:

Which is not a correct statement regarding infrared rays?

Which is not a correct statement regarding ultraviolet radiation?

Assertion (A): Soldiers avoid firing at a target in foggy weather conditions.

Reason (R): In foggy weather, light gets scattered by tiny water droplets, reducing visibility.

Assertion (A): The speed of light for different colours is same in air.

Reason (R): The speed of light for different colours is the different in glass.

Assertion (A): In the pure spectrum, each colour is separated with the other colour, i.e., there is a sharp boundary line separating the colours.

Reason (R): Different colours have different width on the screen.

Assertion (A): Dispersion of white light occurs only at the first surface of a prism.

Reason (R): Deviation of light rays occurs at both surfaces of a prism.

Assertion (A): A radiation X is focused by a proper device on the bulb of a thermometer. Mercury in the thermometer shows a rapid expand.

Reason (R): The radiation X is ultraviolet radiation.

______ radiation are preferred to ordinary visible light for taking photographs in fog.

Sky appears blue due to ______ of visible light.

Clothes soaked in ultramarine and then dried appear whiter and brighter, because ultramarine converts ______ rays into violet, and blue light.

A boy uses a GPS device to locate his missing friend in a crowded area; the system primarily uses ______ to track the location.

The most visible colour is ______.

Match the statements in Column A with those in Column B.

_____ of UV > _____ of microwaves.

The quantity suitable for filling in both the blanks is:

Assertion (A): Sometimes the sky appears reddish in the evening.

Reason (R): Red, being longer in wavelength, scatter more than the other colours.