Waves

Question 1

what is a wave? do waves carry energy? name waves that do? energy in the wave is related to? energy of a wave depends on?

Question 2

intensity formula? also written as? SI unit? how?

Question 3

state doppler effect?
what happens to the wavelength and f when the source is moving toward the observer and when is source is moving away?
v=?

Question 4

listener moving towards stationary source?
what happens to wavelength, speed of sound & frequency?

Question 5

listener moves away from stationary source?
what happens to wavelength, speed of sound & frequency?

Question 6

when source is moving towards stationary listener?
what happens to wavelength & f?

Question 7

when the source is moving away from stationary listener?
what happens to wavelength & f?

Question 8

how does SONAR use doppler effect?

Question 9

how is the velocity of earth’s satellite determined?
speed and direction of aeroplane?
how to create airplane invisibility?

Question 10

how did we know that the earth is expanding?

Question 11

how is doppler effect used in the diagnosis of cardiac diseases?

Question 12

what is superposition of waves?
how to find the displacement?

Question 13

interference of waves?
superpose stationary waves?
superpose to produce beats?

Question 14

coherent waves?
interference? types?

Question 15

constructive interference? what happens?
in case of longitudanal waves?
constructive interference

Question 16

destructive interference? in case of longitudinal waves?
destrucitve interference?

Question 17

conditions for interference?

Question 18

device used to demonstrate interference of sound waves? silence is due to ___ of 2 sound waves?

Question 19

how is the amplitude of sound waves added or subtarcted alternatively? how does the sound grow louder and soft sound? loud & soft sound is due to?

Question 20

how do the noise cancelling headphones work? use what principle? diagram?

Question 21

define beats?
explain with example
what causes constructive & destructive interference?

Question 22

beats frequency? denoted by? 2 sound waves with frequencies 32 Hz & 30Hz? when can beats not be heard as seperate?
beats uses?

Question 23

stationary waves? aka? example?

Question 24

stationary wave is formed by?

Question 25

what are nodes & antinodes? represented by?

Question 26

characteristics of stationary waves? distance between nodes/antinodes? formula?

Answer 26

3

Question 27

when the string is plucked at its middle then? L=? speed of the wave? then f1? what is it called? general formula pg 167

Question 28

when the string is plucked at one quarter of its length? L=? V=? f=? what is the f called

Question 29

when string is plucked at one sixth of its length? L=? v=? f=?

Question 30

How does an organ pipe produce sound? What are some familiar examples of organ pipes? What is the diff. b/w an open organ pipe & a closed organ pipe? In a closed organ pipe, what is the condition at the closed end regarding air molecules? What type of point (node or antinode) arises at the closed end of a tube? At the open end of a tube, what type of point occurs at the right frequency? When does the air column in a tube resonate loudly? Where does the standing wave in a closed tube have an antinode? Where does the standing wave in a closed tube have a node? Does reflection occur at an open end of a tube? What is the distance from a node to an antinode in terms of wavelength? What is the relationship given between the length of the tube (L) and the wavelength (λ₁) for the simplest resonance in a closed pipe?

Answer 30

It produces sound by means of a vibrating air column. flute, trombone, & clarinet. An open organ pipe is open at both ends; a closed organ pipe is closed at one end and open at the other. At the closed end, the molecules of air have very little freedom to oscillate. A node arises at the closed end. At the open end, an antinode occurs at the right frequency. The air column resonates loudly when an antinode occurs at the open end at the right frequency. The standing wave has an antinode at the open end. The standing wave has a node at the closed end. Yes, a portion of the sound wave is reflected back into the tube even at an open end. The distance from a node to an antinode is one-fourth of a wavelength. (The length of the tube equals one-fourth of the wavelength.) | node= doesnt oscillate

Question 31

derive first harmonic for open pipe?

Question 32

derive 2nd harmonic for open pipe?

Question 33

derive 3rd harmonic for open pipe?

Question 34

derive first harmonic for closed pipe?

Question 35

derive 2nd harmonic for closed pipe? general formula pg 171?

Question 36

derive 3rd harmonic for closed pipe?

Question 37

experiment to demonstrate stationary waves? | formative

Question 38

polarization is associated to which waves? what is light wave? EM wave? unpolarized light? polarized light waves? polarization?

Question 39

polarization by a polaroid filter? what are polaroid filters? why is a polaroid filter able to polarize light? what happens when unpolarized light passes through a polaroid filter?

Question 40

I=I cos2 theta explain this formula the eqn. is known as?

Question 41

polarization by reflection? the amount to which polarization occurs depends on? what abt metallic surfaces? how will a person percieve glare here? how does it happen in lakes/seas? polarized glasses?

Question 42

use of polaroids ## Footnote 1

Question 43

use of polaroids | 2

Question 44

diffraction? what if the size of the obstacle is larger than the wavelength of the wave?

Question 45

gravitational wave? what produces gravitational waves? examples of events that could cause a g. wave | formative

Answer 45

cz they are very very small ## Footnote does that mean human cars etc produce g. waves then why can't we detect it

Question 46

interferometer? why are they called it? used for? | formative