Waves

Question 1

Oscillation

Answer 1

To and fro motion of object.

Question 2

Time period (T)

Answer 2

Time taken for one complete oscillation

Question 3

Frequency (f)

Answer 3

Number of oscillation per unit time

Question 4

Displacement (x)

Answer 4

Linear distance travelled from equilibrium

Question 5

Amplitude (A0

Answer 5

It is the maximum distance travelled by vibrating particle from equilibrium on either direction

Question 6

Phase difference

Answer 6

Difference in fraction of oscillation of vibrating particle which can be expressed as an angle.

360t/T or 2πt/T

Question 7

Wave motion

Answer 7

Transfer of energy due to vibration of particles without their net displacement

Question 8

Types of waves

Answer 8

2. Medium based
3. Energy transfer based
4. Movement of particles based

Question 9

Mechanical and Electromagnetic wave

Answer 9

Mechanical Wave: which require medium to travel. ex: sound wave , Water wave
Electromagnetic wave: Which can travel through vacuum/without medium. ex: Light wave

Question 10

Progressive and Stationary wave

Answer 10

Progressive wave: where energy is transferred from one point to another. ex: Light wave, Sound wave.
Stationary wave: where net transfer of energy equals to zero. ex: waves in the string of musical instruments.

Question 11

Transverse and Longitudinal wave.

Answer 11

Transverse wave: where particle vibrates perpendicularly with the direction of wave.
Longitudinal wave: where particle vibrates parallely with the direction of wave

Question 12

Wavelength (λ)

Answer 12

Distance travelled by wave during one oscillation of time period.

Question 13

Wave speed (v)

Answer 13

Distance travelled by wave per unit time.
v=λ/T
v=1/T*λ
v=fλ

Question 14

Intensity (I)

Answer 14

Power transmitted per unit area perpendicularly.
I=P/A
I∝A^2
Intensity ∝ Amplitude^2
I ∝f^2
I ∝ 1/d^2

Question 15

Cathode Ray Oscilloscope (CRO)

Answer 15

It converts any signal to electrical signal and represent it as a voltage-time graph

Question 16

Difference between Transverse and Longitudinal Wave

Answer 16

Transverse-Longitudinal
1. Particles vibrates perpendicularly with the direction of wave- Particles vibrates parallely with the direction of wave.
2.Some waves can travel through vacuum- Medium is required to travel.
3. It can be polarized- Cannot be polarized
4. No variation in pressure and density of medium- Pressure, density varies.
5. Examples: Light wave- Sound wave

Question 17

Compression

Answer 17

It’s a region in longitudinal wave where particles are closer together. Pressure and density is more.

Question 18

Rarefraction

Answer 18

It’s a region in longitudinal wave where particles are away from each other. Pressure and density is less.

Question 19

Electromagnetic Spectrum

Answer 19

Series containing all electromagnetic waves which are arranged according to their frequency or wavelength.

Question 20

Properties of Electromagnetic waves

Answer 20

1. All are transverse wave so they can be polarized
2. They travel through vacuum/ air at a speed of 3*10^8 m/s
3. All obey v=fλ
4. They show reflection, refraction ,diffraction, interference etc
5. When they travel from one to another medium, their speed and wavelength changes but frequency always remain same.

Question 21

Doppler Effect

Answer 21

When there is relative motion between source and observer, apparent change in frequency/wavelength to the observer is known as doppler effect.
f0=fs.v/v+-vs
away=+ , towards= =

Question 22

Polarization

Answer 22

Producing vibration in a single direction

Question 23

Malus’s law

Answer 23

I =I0 cos^2 θ
A= A0 cosθ
% of transmitted intensity= I/I0 * 100%
=cos^2 θ * 100%

Question 24

Phase difference

Answer 24

0/360/2πrad = λ,2λ,3λ …. nλ
180/πrad = 0.5λ,1.5λ,2.5λ ….. n-1/2λ