Waves

Question 1

What is wave motion?

Answer 1

A disturbance that travels from one place to another.

Question 2

What is displacement in waves?

Answer 2

How far a point moves from its resting position.

Question 3

What is amplitude?

Answer 3

The highest point a wave reaches from its resting level.

Question 4

What is the period of a wave?

Answer 4

Time taken for one full wave to pass.

Question 5

What is frequency?

Answer 5

Number of waves passing in one second.

Question 6

What is the formula of frequency?

Answer 6

f = 1 / T

Question 7

What is wavelength?

Answer 7

The distance between two same points on a wave (like crest to crest).

Question 8

What is wave speed?

Answer 8

How fast the wave moves forward.

Question 9

Do progressive waves transfer energy?

Answer 9

Yes, they carry energy from one place to another.

Question 10

What is the basic wave equation?

Answer 10

v = f × λ

Question 11

How is v = fλ derived?

Answer 11

λ is distance, T is time, so v = λ/T, and f = 1/T → v = fλ

Question 12

What is phase difference?

Answer 12

The gap between two waves measured in angle or cycle.

Question 13

What is phase difference formula?

Answer 13

Phase difference = (x / λ) × 2π

Question 14

What is in-phase?

Answer 14

Waves are in-step (same direction), phase difference = 0 or 2π.

Question 15

What is antiphase?

Answer 15

Waves are opposite, phase difference = π or 3π.

Question 16

What is a displacement-distance graph?

Answer 16

Shows wave shape at a fixed moment.

Question 17

What is a displacement-time graph?

Answer 17

Shows how one point moves over time.

Question 18

What is a CRO (Cathode Ray Oscilloscope)?

Answer 18

A machine to measure wave’s frequency and amplitude.

Question 19

What is Y-gain in CRO?

Answer 19

Shows how much voltage is shown per division (for amplitude).

Question 20

What is time-base in CRO?

Answer 20

Shows time per division (used to find period).

Question 21

What is intensity of a wave?

Answer 21

How much energy passes through an area per second.

Question 22

What is the formula for intensity?

Answer 22

Intensity = Power / Area

Question 23

How does intensity relate to amplitude?

Answer 23

Intensity ∝ Amplitude²

Question 24

For a point source

Answer 24

what is intensity formula?

Question 25

What happens to intensity if distance increases?

Answer 25

Intensity decreases (Intensity ∝ 1/r²)

Question 26

What happens to amplitude if distance increases?

Answer 26

Amplitude gets smaller (Amplitude ∝ 1/r)

Question 27

What is the Doppler Effect?

Answer 27

Change in wave frequency due to movement of source or observer.

Question 28

What happens if source moves towards observer?

Answer 28

Frequency increases (blue shift).

Question 29

What happens if source moves away from observer?

Answer 29

Frequency decreases (red shift).

Question 30

What is the Doppler Effect formula?

Answer 30

f₀ = (v / (v ± vₛ)) × fₛ

Question 31

What is a transverse wave?

Answer 31

Particles move at 90° to wave direction (e.g. light).

Question 32

Can transverse waves be polarized?

Answer 32

Yes, only transverse waves can be polarized.

Question 33

What is a longitudinal wave?

Answer 33

Particles move in same direction as wave (e.g. sound).

Question 34

Can longitudinal waves be polarized?

Answer 34

No, they cannot be polarized.

Question 35

What is polarization?

Answer 35

Making wave vibrate in only one direction.

Question 36

What is Malus’ Law formula?

Answer 36

I = I₀ × cos²θ

Question 37

How is intensity related to amplitude?

Answer 37

I ∝ A²

Question 38

What are electromagnetic waves?

Answer 38

Waves like light that don’t need a medium and travel at light speed.

Question 39

What is speed of all EM waves?

Answer 39

3 × 10⁸ m/s

Question 40

What is the wavelength range of visible light?

Answer 40

400 nm to 700 nm

Question 41

Do EM waves transfer energy?

Answer 41

Yes, they do.

Question 42

Are EM waves transverse or longitudinal?

Answer 42

They are transverse waves.