Physics Test 178

Result

Physics Test 178

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
4 / -1

Let S₁ and S₂ be the two slits in Young’s double slit experiment. If central maxima is observed at P and angle then the fringe width for the light of wavelength λ will be. (Assume θ to be a small angle)

A
λ/θ

B
λθ

C
2λ/θ

D
λ/2θ

Solution
Question 2
4 / -1

Figure shows two coherent sources S1-S2 vibrating in same phase. AB is an irregular wire lying at a far distance from the sources S1 and S2. How many bright spots will be seen on the wire, including points A and B.

A
2

B
3

C
4

D
more than 4

Solution
Question 3
4 / -1

If the ratio of the intensity of two coherent sources is 4 then the visibility [(I_max- I_min)/(I_max+ I_min)] of the fringes is

A
4

B
4/5

C
3/5

D
9

Solution
Question 4
4 / -1

In Young’s double slit experiment, we get 60 fringes in the field of view of monochromatic light of wavelength 4000 A⁰. If we use monochromatic light of wavelength 6000 A⁰, then the number of fringes that would be obtained in the same field of view is :

A
60

B
90

C
40

D
1.5

Solution

λ ∞ (Fringe width)

Higher 'λ' means wider fringes.

At higher wavelength, same space on the screen is occupied by wider fringes, and hence lesser number of fringes.
Question 5
4 / -1

If the distance between the first maxima and fifth minima of a double slit pattern is 7mm and the slits are separated by 0.15 mm with the screen 50 cm from the slits, then wavelength of the light used is

A
600 nm

B
525 nm

C
467 nm

D
420 nm

Solution
Question 6
4 / -1

The path difference between two interfering waves at a point on the screen is λ/6. The ratio of intensity at this point and that at the central bright fringe will be : (Assume that intensity due to each slit is same)

A
0.853

B
8.53

C
0.75

D
7.5

Solution
Question 7
4 / -1

In a Young’s double slit experiment, the separation between the slits is d, distance between the slit and screen is D (D >> d). In the interference pattern, there is a maxima exactly in front for each slit. Then the possible wavelengths used in the experiment are :

A

B

C

D
None Of these

Solution
Question 8
4 / -1

A point source of light is kept at the centre of a solid transparent sphere. The sphere is surrounded by air . The refractive index of material of sphere for which the rays incident from point source on glass–air interface will suffer total internal reflection is:

A
1.5

B
√2

C
2

D
Total internal reflection will not occur for any value of refractive index of the sphere

Solution

All rays originating from point source are incident normally on glass air interface, hence no ray suffers total internal reflection.
Question 9
4 / -1

A point object ' O ' is at the centre of curvature of a concave mirror. The mirror starts to move at a speed u, in a direction perpendicular to the principal axis. Then the initial velocity of the image is:

A
2 u, in the direction opposite to that of mirror's velocity

B
2 u, in the direction same as that of mirror's velocity

C
zero

D
u, in the direction same as that of mirror's velocity.

Solution
Question 10
4 / -1

In the figure shown an object ‘AB’ makes small angle with the normal line ‘PQ’. The length of ‘AB’ is l. The refractive index of the slab is ‘n’ and the surrounding medium is air. ‘AB’ is seen with the help of paraxial rays, from the left side of the slab. The size of the image of AB is

A

B

C

D

Solution

Every point of the image will be at distance towards left of the object.The image will be parallel to 'AB' and of the same size.