Spectrum

Appeared in 9 of the 11 available papers.

Examined in

9 of 11 papers

Appears in most years

Typically worth

4.9 marks

Average per paper it appears in · 44 marks in total

Usual form

Short answer

31% of this chapter's 36 questions

Needs a diagram

17%

6 questions carry a figure — practise drawing them

Question-type distribution

Short answer11
MCQ9
Identification8
Numerical3
Reasoning3
Diagram1
Definition1

Most frequent topics

Electromagnetic spectrum / scattering 12Spectrum / scattering 3Infrared radiation 3Electromagnetic spectrum order 2Common properties of electromagnetic waves 2Infrared radiation and greenhouse gases 1Detecting infrared radiation 1Speed of light and wavelength in vacuum 1

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Print chapter question bank

Showing 25 of 36 matching questions (44 marks).

25 questions

1

Choose the correct answers to the questions from the given options. (Do not copy the questions, write the correct answers only.)

1(v)2026

MCQEasy1 mark

When a blackened bulb thermometer is moved beyond the red region of the visible spectrum, there is a rapid rise in the temperature. This is due to the presence of : (a) Infrared radiations (b) Ultraviolet radiations (c) X-rays (d) Radio waves

1(viii)2026

MCQEasy1 mark

Assertion (A) : Tiny air molecules scatter blue light more than red light. Reason (R) : The refractive index of a medium is greater for blue light than red light. (a) (A) is true but (R) is false. (b) (A) is false but (R) is true. (c) Both (A) and (R) are true and (R) is correct explanation of (A). (d) Both (A) and (R) are true and (R) is not the correct explanation of (A).

4(iii)(a)2026

IdentificationEasy1 mark

Name the electromagnetic radiation used to detect fake currency.

1

Choose the correct answers to the questions from the given options. (Do not copy the questions, write the correct answers only.)

1(v)2025

MCQEasy1 mark

Which one of the following combinations is the correct ascending order of electromagnetic waves in terms of wavelength? (a) Gamma-rays, visible light, microwaves (b) Microwaves, visible light, gamma-rays (c) Gamma-rays, microwaves, visible light (d) Microwaves, gamma-rays, visible light

5(iii)(a)

Name the radiations :

5(iii)(a)(1)2025

IdentificationEasy1 mark

for which a quartz prism is used to study the spectrum.

5(iii)(a)(2)2025

IdentificationEasy1 mark

which are used in remote sensing devices.

5(iii)(a)(3)2025

IdentificationEasy1 mark

which are used in traffic signals in India.

5(iii)(b)2025

IdentificationEasy1 mark

Name one property common to all electromagnetic radiations.

1

Choose the correct answers to the questions from the given options. (Do not copy the questions, write the correct answers only.)

1(v)2024

MCQEasy1 mark

Assertion (A) : Ultraviolet radiations are scattered more as compared to the microwave radiations. Reason (R) : Wavelength of ultraviolet radiation is more than the wavelength of microwave radiation. (a) Both A and R are true. (b) A is true but R is false. (c) A is false but R is true. (d) Both A and R are false.

4(ii)

Below is an incomplete table showing the arrangement of electromagnetic spectrum in the increasing order of their wavelength. Complete the table.

Figure for this question

4(ii)(a)2024

IdentificationEasy1 mark

Identify the radiation A.

4(ii)(b)2024

IdentificationEasy1 mark

Name the radiation used to detect fracture in bones.

4(ii)(c)2024

IdentificationEasy1 mark

Name one property common to both A and Radio waves.

4(iii)(a)2024

ReasoningModerate1 mark

Why do we use red colour as a danger signal on the top of a skyscraper?

4(iii)(b)

The diagram below shows the path of a blue ray through the prism :

Figure for this question

4(iii)(b)(2)2024

Short answerEasy1 mark

What is the measure of the angle of this prism (A)?

5(iii)(a)2023

ReasoningModerate2 marks

Infrared radiations are used in warfare. Explain with reason, why.

5(iii)(b)

A ray of light is incident at 45° on an equilateral prism in the diagram below.

Figure for this question

5(iii)(b)(1)2023

Short answerEasy1 mark

Name the phenomenon exhibited by the ray of light when it enters and emerges out of the prism.

5(iii)(b)(2)2023

Short answerEasy1 mark

State the cause of the above phenomenon mentioned by you.

Select the correct option for each of the following questions

MCQEasy1 mark

The deviation produced by an equilateral prism does not depend on: (a) the angle of incidence. (b) the size of the prism. (c) the material of the prism. (d) the colour of light used.

MCQEasy1 mark

The refractive index of a diamond is 2.4. It means that: (a) the speed of light in vacuum is equal to 1/2.4 times the speed of light in diamond (b) the speed of light in the diamond is 2.4 times the speed of light in a vacuum. (c) the speed of light in a vacuum is 2.4 times the speed of light in the diamond, (d) the wavelength of light in diamond is 2.4 times the wavelength of light in vacuum.

MCQEasy1 mark

The colour of white light which is deviated least by a prism is: (a) green (b) yellow (c) red (d) violet

MCQEasy1 mark

The wave length range of visible light is: (a) 40 nm to 80 nm (b) 4000 nm to 8000 nm (c) 4 nm to 8 nm (d) 400 nm to 800 nm

MCQEasy1 mark

The ratio of velocities of light of wavelength 400 nm and 800 nm in a vacuum is: (a) 1:1 (b) 1:2 (c) 2:1 (d) 1:3

3(a)

The wave lengths for the light of red and blue colours are nearly 7.8 × 10–7 m and 4.8 × 10–7 m respectively.

3(a)(i)2020

Short answerEasy1 mark

Which colour has the greater speed in a vacuum ?

3(a)(ii)2020

Short answerEasy1 mark

Which colour has a greater speed in glass ?

7(a)

Give reasons for the following :

7(a)(i)2020

Short answerEasy1.5 marks

Clouds appear white.