| 1 |
The minimum number of lenses used in compound microscope is |
1
2
3
4
|
| 2 |
The transmitter in optical fiber system contains a device called |
LED
Diode
Transistor
None of these
|
| 3 |
Analyzer is use to |
Polarize the light
Un-polarize the light
Check whether the light is polarized or un polarized
Rotate the plane of polarized light
|
| 4 |
For total internal reflection to take place, the angle of incidence must be ______ than critical angle and the light should travel from ______ to ______ medium |
Greater, rarer, denser
Smaller, rarer, denser
Smaller, denser, rarer
Greater, denser, rarer
|
| 5 |
The variation if focal length of a lens when we pass from the central portion out words (to words the lens edges) is known as |
Astigmatism
Chromatic
Spherical aberration
Coma
|
| 6 |
Which of the following light move faster in water |
Red
Violet
Green
Blue
|
| 7 |
An optical fiber of ______ cm in diameter id equivalent to 7.62 cm diameter bundle of ______ wires to carry the same amount of signals |
0.6, aluminum
6.0, copper
0.6, copper
6.0, aluminum
|
| 8 |
The fiber of which refractive index ______ gradually as move from central core to its periphery is called ______ index fiber |
Decreases, multi-mode graded
Increases, single mode step
Either of A or B
Increases, multi-mode step
|
| 9 |
Cladding means a layer of ______ refractive index over the central core of ______ refractive index |
Lower, lower
Higher, lower
Lower, higher
None of these
|
| 10 |
A fiber of 50μm diameter capable of carrying white light at ______ distances is called ______ index fiber |
Large, multi-mode step
Small, multi-mode step
Small, multi-mode graded
Large, single mode step
|
| 11 |
Propagation of light in an optical fiber requires that light should be |
Refracted from air to fiber
Continuously refraction
Totally reflected within the fiber
Both B and C
|
| 12 |
If we know the refractive index of glass, speed v of light in the glass can be found by |
v = c n
v = c/n
v = n/c
None of these
|
| 13 |
Which type of optical fiber has the largest diameter |
Single mode step index fiber
Multi-mode step index fiber
Multi-mode graded index fiber
None of these
|
| 14 |
Let a ray of light enters from air into two media of different refractive indices. The speed of light will be ______ to refractive index |
Directly proportional
Inversely proportional
Sometimes inversely
Equal
|
| 15 |
The property of light which makes light possible to be transmitted into inaccessible place is |
Interference
Diffraction
Polarization
None of these
|
| 16 |
The laser light used in an optical fiber system has a wavelength equal to |
3<span style="color: rgb(34, 34, 34); font-family: "Times New Roman"; font-size: 24px; text-align: center; background-color: rgb(255, 255, 224);"><i>μ</i></span>m
5<span style="color: rgb(34, 34, 34); font-family: "Times New Roman"; font-size: 24px; text-align: center; background-color: rgb(255, 255, 224);"><i>μ</i></span>m
1.3<span style="color: rgb(34, 34, 34); font-family: "Times New Roman"; font-size: 24px; text-align: center; background-color: rgb(255, 255, 224);"><i>μ</i></span>m
6<span style="color: rgb(34, 34, 34); font-family: "Times New Roman"; font-size: 24px; text-align: center; background-color: rgb(255, 255, 224);"><i>μ</i></span>m
|
| 17 |
For glass-air boundary, the value of the critical angle is |
42°
45°
30°
60°
|
| 18 |
The light waves and radio waves differ in |
Speed
Frequency
Wavelength
Both B and C
|
| 19 |
|
|
| 20 |
A material having high refractive index has |
Low density
High density
Zero density
None of these
|
| 21 |
Cladding in an optical fiber is used to |
Absorb unneccessary light
Produce total internal reflection
Transmit light
Filter light
|
| 22 |
The ability of an instrument of reveal the minor details of an object under examination is called |
Resolution
Magnification
Resolving power
Dispersion
|
| 23 |
The resolving power of a grating spectrometer is |
|
| 24 |
In case of reflection of ray within a denser medium, angle of incidnet is ______ -angle of reflection |
Greater then
Smaller then
Equal to
None of these
|
| 25 |
A ray of light passing from a rarer to a denser medium |
Bends towards normal
Bends away from normal
Suffers no change in direction
None of these
|
| 26 |
For which color of light the refractive index of glass is larger |
Red
Green
Blue
Violet
|
| 27 |
A shortsighted person can see clearly |
Near objects
Far objects
Objects at 25 cm
Objects at infinity
|
| 28 |
To get higher magnification we must use |
Simple microscope
A convex lens
A compound microscope
All of these
|
| 29 |
The speed of light in a medium depends upon |
Its wavelength
Its frequency
Refractive index
All of these
|
| 30 |
The magnification is negative for |
Real image
Virtual image
Sometimes for real sometimes for real
Only for cancave lens
|
| 31 |
The magnifying power of a compound microscope can be increased if we use objective lens of |
Large focal length
Small focal length
Same focal length
None of these
|
| 32 |
The limit of which a microscope can be used to resolve details of an object, demands |
Wider objective and light of short wavelength
Narrow objective and light of short wavelength
Narrow objective and light of longer wavelength
None of these
|
| 33 |
A lens of 2 cm focal length is to be used as a magnifying glass. Its magnification is |
13.5
12.5
0.5
2.5
|
| 34 |
In the formulaαamino = 1.22λ/D, D denotes |
Distance between source and the object
Diameter of lens
Power of the lens in Diopters
None of these
|
| 35 |
A grating with high resolving power can distinguish ______ difference in ______ |
Smaller, amplitude
Greater, wavelength
Smaller, wavelength
Greater, intensity
|
| 36 |
The angle of incidence at which angle of refraction becomes 900 is called |
Incident angle
Angle of refraction
Critical angle
Phase angle
|
| 37 |
The image of an object 5 mm length is only 1 cm high. The magnification of the lens is |
1
0.2
2
0.1
|
| 38 |
When the same object is viewed at a shorter distance the image on the retina of eye is ______ and so the object appears ______ |
Greater, small
Smaller, smaller
Smaller, larger
Greater, larger
|
| 39 |
The refractive index of a medium is defined as a ratio |
|
| 40 |
Certain light of wavelength 600 nm is used to view an object under the microscope. If the aperture of its objective is 1.22 cm, then the limiting angle of resolution will be |
6 x 10<sup>-5</sup>rad
7 x 10<sup>-5</sup>rad<sup></sup>
8 x 10<sup>-5</sup>rad
None of these
|