| 1 |
In the formula R = N x m for diffraction grating, N denotes: |
No. of lines/cm
No. of lines/meter
Total number of lines
None of above
|
| 2 |
A grating with high resolving power can distinguish _______ difference in wavelengths : |
Larger
Zero
None of these
Smaller
|
| 3 |
A grating with high resolving power can distinguish _______ difference in wavelengths : |
Smaller
Larger
Zero
None of these
|
| 4 |
Resolving power in mth order diffraction for grating is given by: |
R = N x m
None of these
R = m/N
R = N/m
|
| 5 |
Resolving power in mth order diffraction for grating is given by: |
R = N/m
R = m/N
R = N x m
None of these
|
| 6 |
To see the minor details of the object by microscope, it should have: |
High magnifying power
High resolving power
Am objective of larger focal length
None of these
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| 7 |
The focal length of convex lens having magnifying power of 5.55 is: |
5.5 cm
5 cm
4.5 cm
6 cm
|
| 8 |
The image of an object 5 mm length is only 1 cm high. The magnification produced by lens is: |
1
0.2
2
0.1
|
| 9 |
A magnifier gives an image which is: |
Virtual, inverted
Real, erect
Virtual, erect
Real, inverted
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| 10 |
The magnifier forms a virtual image of the object at: |
None of these
Both A and B are correct
Much farther than the least distance
Least distance of distinct vision
|
| 11 |
The magnifier forms a virtual image of the object at: |
None of these
Least distance of distinct vision
Much farther than the least distance
Both A and B are correct
|
| 12 |
The size of the image is maximum when its distance from the magnifying glass is: |
0.10 m
0.15 m
0.20 m
0.25 m
|
| 13 |
The ratio of the size of the image to that of object is called: |
Focal length
Aperture
Linear magnification
Principal axis
|
| 14 |
If the object is placed at 12 cm distance from a convex lens of focal length 6 cm, then we get an image of ____ as that of object: |
Double the size
Same size
Half the size
None of these
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| 15 |
When the same object is viewed at a shorter distance, the image on the retina of the eye is _____ the so the object appears: |
Greater, smaller
Smaller, smaller
Smaller, larger
Greater, larger
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| 16 |
A virtual image is formed when object is placed: |
Within focal length of a convex lens
Near the focal point of a concave lens
Both A and B
Away from 2F of a convex lens
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| 17 |
For the virtual image, option _______ is not correct: |
1/p = 1/f -1/q
1/f = 1/p -1/q
1/p=1/p-1/f
1/p=1/f+1/q
|
| 18 |
A ray passing through optical center of a lens, after refraction: |
Passes through focus
Go deviated
Retraces its path
Both B and C
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| 19 |
If the object and its image are located at a distance of 5 cm from the focus of a convex lens, the focus length of the lens will be: |
5 cm
10 cm
20 cm
25 cm
|
| 20 |
Conventionally, all the distance p, q, f are measured from _____ of the lens: |
Focus
Optical center
Edges
None of these
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| 21 |
Least distance of distinct vision of an old man possibly becomes: |
A little less than 25 cm
A little more than 25 cm
Much less than 25 cm
None of these
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| 22 |
The ratio of the diameter of two convex lenses is _____-the ratio of their focal lengths: |
Greater than
Less than
Equal to
None of these
|
| 23 |
If the focal length of the convex lens is 5 cm, then to get the real and inverted image of the same size as that of object, the object should be placed at: |
15 cm
10 cm
20 cm
5 cm
|
| 24 |
If the focal length of the convex lens is 5 cm, then to get the real and inverted image of the same size as that of object, the object should be placed at: |
5 cm
20 cm
10 cm
15 cm
|
| 25 |
How is the image formed by a convex lens affected if the upper half of the lens is covered with a paper: |
The upper half of the image is cut off
The brightness of the image is reduced
The brightness of the image is increased
No effect at all
|
| 26 |
If the object is situated at focus of a convex lens, then its image is formed at: |
F
2F
Infinity
None of these
|
| 27 |
When the object lies between F and 2F, the image formed by is formed at: |
Virtual
Diminished
Erect
Real
|
| 28 |
When the object lies between F and 2F, the image formed by is formed at: |
Real
Virtual
Diminished
Erect
|
| 29 |
A convex lens acts as diverging lens when the object is placed: |
Beyond 2F
At 2F
With focal length
Between F and 2F
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| 30 |
A convex lens acts as diverging lens when the object is placed: |
Between F and 2F
At 2F
With focal length
Beyond 2F
|