MDCAT Physics Chapter 7 MCQ Test With Answer for (Light )

Which of the following is the most common method to obtain polarized light?

• selective absorption A
• reflection from different surfaces B
• refraction through crystals C
• scattering by small particles D

The practical use of services by optic fiber is

• Two way television A
• World processing B
• Image transmitting and receiving equipment C
• All of these D

For a system to transmit thousands of telephones conversations, several television programs and numerous data signals, it need the following number so threads of optical fibre

• 100 to 200 A
• 1000 to 10000 B
• 100 to 1000 C
• 1 or 2 D

If the bright fringe into be observed then we have relation

• Y = mLd/λ A
• Y = mλL/d B
• Y = λd/mL C
• Y = λL/md D

Sunset makes sky appears reddish because of:

• Diffraction of sun rays A
• Refraction of light B
• Scattering of light from dust particles C
• Polarization of ligth D

Electromagnetic waves from a source were found to be significantly diffracted when passing through gaps of the order of 10 m. What type of waves are they likely to be?

• gamma waves A
• light waves B
• microwaves C
• radiowaves D

How many phone calls can be carried by single mode step index fibre

• 25000 A
• 96000 B
• 14000 C
• 21000 D

The velocity of light in vacuum can be changed by changing:

• Frequency A
• Amplitude B
• Wavelength C
• None of these D

The advantage/advantages of fiber optics than radio wave carriers

• Much wider band width A
• Capability B
• Immunity C
• All of these D

Magnification of a convex lens is

• M = p/d A
• M = p/q B
• M = q/p C
• None of these D

The critical angle for a ray of light suffering total internal reflection will be smallest for the ray traveling from

• Water to glass A
• Water to air B
• Glass to air C
• Glass to water D

A fiber of 50μm diameter capable of carrying white light at ______ distances is called ______ index fiber

• Large, multi-mode step A
• Small, multi-mode step B
• Small, multi-mode graded C
• Large, single mode step D

The superposition of the two waves of same frequency and amplitude travelling in the same direction gives rise to an effect called:

• Diffraction A
• Interference B
• Polarization C
• Dispersion D

The optical fibre is covered for protection with

• rubber jacket A
• plastic jacket B
• steel jacket C
• copper jacket D

The phase difference between two points on a wave front will be

• 0° A
• 4π B
• 2π C
• π/2 D

The least distance of he distinct vision is

• 20 cm A
• 22 cm B
• 25 cm C
• 30 cm D

• 
  A
• 
  B
• 
  C
• 
  D

The spacing between lines of diffraction grating is

• Opaque A
• Transparent B
• Semi-transparent C
• None of these D

For the normal setting of a telescope

• Only the object is at infinity A
• Only the final image is at infinity B
• Both the object and the final image is at infinity C
• Neither the object nor the final image has to be at infinity D

A diffraction pattern is obtained using a beam of red light What will happen if the red light is replaced by blue light?

• No change A
• Diffraction bands become narrower and crowded together B
• Bands become broader and farther apart C
• Bands disappear D