Single and two sources interference

Question 1

Principle of Superposition

Answer 1

Principle of superposition state that when two or more waves of the same kind interfere at a point, the RESULTANT DISPLACEMENT at that point is the is the vector sum of displacement of each wave

Question 2

interference

Answer 2

Interference is an effect when two or more waves overlap to produce a NEW WAVE PATTERN with
CHANGE IN AMPLITUDE

Question 3

Constructive Intereference

Answer 3

Constructive interference is an effect where two or more waves overlap at a point such that the displacement of the resultant wave is larger than the maximum displacement of individual waves

Question 4

Destructive Interference

Answer 4

Destructive Interference is an effect where two or more waves meet at a point such that the resultant displacement is smaller than the largest individual displacement

Question 5

Coherent

Answer 5

Sources maintain a constant phase difference

Question 6

Conditions for interference pattern to be observable

Answer 6

1) The amplitude must be approximately the same
2) Sources must be COHERENT
3) Transverse waves–If one source is unpolarized another source is unpolarized too. If one source is polarized, the other source must be polarised along the same axis

Question 7

If white light where use

Answer 7

The central spot is still white since all colors travel the same distance and they will meet there in phase

Other bright spots will have various colours diffracted to their wavelengths. The longer the wavelength, larger the angle of diffraction

Question 8

Conditions to resolve 2 objects

Answer 8

To just able to resolve the 2 objects,

1) the central maximum of diffraction pattern of one object
2) must fall at the first minimum of the diffraction pattern of the other diffraction pattern

Question 9

Conditions to resolve 2 objects

Answer 9

To just able to resolve the 2 objects,

1) the central maximum of diffraction pattern of one object
2) must fall at the first minimum of the diffraction pattern of the other diffraction pattern

Question 10

Rayleigh’s criterion

Answer 10

Two images formed by a SLIT are just distinguishable if

1) Central Maximum of diffraction pattern for ones imagine
2) falls on the first minimum of the diffraction pattern for the other image

Minimum angle of resolution is =