IGCSE Physics 0625 — Topic 3: Waves

Question 1

Which of the following is an example of a longitudinal wave?

ALight travelling through space BA wave on a vibrating guitar string CSound travelling through air DA water wave on a pond

Question 2

A wave has a speed of 3.0 m/s and a wavelength of 0.15 m. What is the frequency?

A0.45 Hz B0.05 Hz C2.0 Hz D20 Hz

Question 3

The wavelength of a transverse wave is the distance between:

AA crest and the next trough BThe rest position and a crest CTwo consecutive compressions DTwo consecutive crests

Question 4

In a ripple tank, what happens to waves when they enter a shallower region at an angle?

AThey speed up and bend away from the normal BThey slow down and bend towards the normal CThey slow down and bend away from the normal DTheir frequency changes

Question 5

A student counts 12 waves passing a point in 4 seconds. What is the frequency?

A48 Hz B0.33 Hz C3.0 Hz D16 Hz

Question 6

Diffraction is most significant when the width of the gap is:

AMuch larger than the wavelength BMuch smaller than the wavelength CAbout the same as the wavelength DExactly twice the wavelength

Question 7

Which wave property is directly related to the energy carried by the wave?

AWavelength BFrequency CAmplitude DSpeed

Question 8

A radio wave has a frequency of 100 MHz (100 × 10⁶ Hz). Radio waves travel at 3.0 × 10⁸ m/s. What is the wavelength?

A30 m B3.0 m C0.3 m D300 m

Question 9

When waves reflect off a straight barrier, which statement is true?

AThe frequency of the wave changes BThe speed of the wave doubles CThe wavelength of the wave halves DThe angle of incidence equals the angle of reflection

Question 10

On a displacement–time graph of a wave, the period is:

AThe maximum displacement from the rest position BThe time for one complete oscillation CThe distance between two crests DThe number of waves per second

Question 11

A student shines a ray of light at a plane mirror. The angle between the incident ray and the reflected ray is 110°. What is the angle of incidence?

A110° B70° C55° D35°

Question 12

Light travels from water (n = 1.33) into air. The critical angle for water is approximately:

A41.8° B48.8° C90.0° D33.3°

Question 13

A converging lens is used as a magnifying glass. For this to work, the object must be placed:

ABeyond 2F BAt 2F CBetween F and 2F DBetween the lens and F

Question 14

The refractive index of diamond is 2.42. What is the critical angle for diamond?

A24.4° B41.1° C65.6° D48.8°

Question 15

When a ray of light enters a glass block from air, it bends towards the normal. This is because:

ALight speeds up in glass BLight slows down in glass CLight changes frequency in glass DLight changes colour in glass

Question 16

In the visible spectrum produced by a prism, which colour is refracted the most?

ARed BYellow CGreen DViolet

Question 17

A ray of light in glass (n = 1.5) hits the glass–air boundary at 50° to the normal. What happens?

AThe ray refracts away from the normal BThe ray refracts towards the normal CThe ray undergoes total internal reflection DThe ray passes straight through without bending

Question 18

An object is placed at the focal point (F) of a converging lens. The image formed is:

AAt 2F, real and inverted BBetween F and 2F, real and diminished CAt infinity DVirtual, upright, and magnified

Question 19

What does “monochromatic” light mean?

ALight that is very bright BLight of a single wavelength (or colour) CLight that has been polarised DLight that travels in straight lines

Question 20

An image formed by a plane mirror is always:

AReal, inverted, and the same size BVirtual, upright, and the same size CVirtual, inverted, and magnified DReal, upright, and diminished

Question 21

Which property do ALL electromagnetic waves share?

AThey all have the same wavelength BThey can all pass through the human body CThey all travel at the same speed in a vacuum DThey are all visible to the human eye

Question 22

Infrared radiation is used for:

AKilling bacteria in hospitals BCommunicating with satellites CThermal imaging cameras DTaking X-ray photographs

Question 23

Which EM wave is used to treat cancer by destroying tumour cells?

AInfrared BMicrowaves CRadio waves DGamma rays

Question 24

A communications satellite in geostationary orbit:

AOrbits over the North and South poles BTakes 24 hours to orbit and stays above the same point on Earth COrbits at a low altitude of about 200 km DMoves across the sky as seen from the ground

Question 25

Which type of EM radiation is used for cooking food in an oven that heats from inside?

AInfrared BUltraviolet CMicrowaves DRadio waves

Question 26

The main danger of excessive exposure to ultraviolet radiation is:

AHearing loss BBurns to internal organs CDamage to skin cells, potentially causing cancer DImmediate blindness in all cases

Question 27

An analogue signal differs from a digital signal because:

AIt can only carry sound, not data BIt varies continuously in amplitude and/or frequency CIt uses only two voltage levels DIt cannot be transmitted through wires

Question 28

Radio waves are used for:

AMedical imaging of bones BSterilising surgical equipment CBroadcasting television and radio programmes DTreating skin diseases

Question 29

Which statement about the EM spectrum is correct?

AGamma rays have the longest wavelength BRadio waves have the highest frequency CAll EM waves are transverse waves DMicrowaves cannot travel through a vacuum

Question 30

Which type of EM radiation can pass through soft tissue but is absorbed by bone?

AVisible light BRadio waves CX-rays DMicrowaves

Question 31

In a longitudinal wave, a region where particles are spread apart is called:

AA crest BA compression CA rarefaction DAn amplitude

Question 32

The speed of sound in air is approximately:

A3 × 10⁸ m/s B1500 m/s C340 m/s D3400 m/s

Question 33

A bat emits an ultrasound pulse that bounces off an insect 8.5 m away. The speed of sound in air is 340 m/s. How long does the pulse take to return to the bat?

A0.025 s B0.050 s C0.0125 s D0.1 s

Question 34

When a veena player plucks a thicker, heavier string instead of a thinner one (same length and tension), the sound produced has:

AA higher pitch BA lower pitch CA greater speed DThe same pitch but louder

Question 35

A student is trying to measure the speed of sound using an echo method. She stands 200 m from a large wall and claps her hands. She times 10 echoes and finds the total time is 12.0 s. What is the speed of sound?

A167 m/s B333 m/s C240 m/s D400 m/s

Question 36

Which of the following sounds can be heard by a healthy human ear?

A10 Hz B5000 Hz C25 000 Hz D50 000 Hz

Question 37

Ultrasound is preferred over X-rays for scanning a baby during pregnancy because:

AUltrasound gives clearer images BUltrasound is cheaper CUltrasound is non-ionising and safer for the baby DX-rays cannot pass through the body

Question 38

Sound travels fastest through:

AA vacuum BAir at room temperature CWater at room temperature DA steel rail

Question 39

A whistle produces a note of frequency 2000 Hz. The speed of sound is 340 m/s. What is the wavelength of this sound?

A0.17 m B5.88 m C680 000 m D1.7 m

Question 40

During a school assembly in Bangalore, a teacher at the back of the hall cannot hear the speaker clearly due to echoes. Which material should be used on the walls to reduce echoes?

AGlass mirrors BPolished marble tiles CSoft fabric curtains and acoustic panels DSmooth metal sheets

Paper 2 — Multiple Choice

Exam Complete!

Section A: General Properties of Waves (3.1)

Section B: Light (3.2)

Section C: Electromagnetic Spectrum (3.3)

Section D: Sound (3.4)