NTSE SAT Physics Light Eye and Optical Instrument MCQs

Question: magnifying power of an astronomical telescope is 15. Then ratio of the focal length of the objective to the focal length of the eye piece is :

• a) 15
• b) 1/15
• c) 11.5
• d) None

Answer: 15

Question: The defect of vision in which person can seen distant objects clearly but nearly object looks blurred is :

• a) Myopia
• b) Astigmatism
• c) Hypermetropia
• d) Presbyopia

Answer: Hypermetropia

Question: In compound microscope then lens with lesser focal length is called :

• a) Objective lens
• b) Eye lens
• c) Micro scopic lens
• d) Concave lens

Answer: Objective lens

Question: The distance of the eye lens from the retina is x. For a normal eye, the maximum focal length of the eye lens is :

• a) < x
• b) > x
• c) 2x
• d) x

Answer: x

Question: A long sighted person has a minimum distance of distinct vision of 50 cm. He wants to reduce it to 25 cm. He should use a :

• a) Concave lens of focal length 25 cm.
• b) Concave lens of focal length 50 cm.
• c) Convex lens of focal length 25 cm.
• d) Convex lens of focal length 50 cm.

Answer: Convex lens of focal length 50 cm.

Question: In the human eye, which part of the eye receives the optical image of the object and then converts it into optical pulses ?

• a) Cornea
• b) Sclerotic
• c) Eye lens
• d) Retina

Answer: Retina

Question: Primary pigments are :

• a) Red, Blue, Yellow
• b) Red, Cyan, Magenta
• c) Yellow, Cyan, Magenta
• d) Blue, Cyan, Magnet

Answer: Yellow, Cyan, Magenta

Question: A lens used as magnifying glass is :

• a) Double convex
• b) Double concave
• c) Any spherical lens
• d) None of these

Answer: Double convex

Question: The intensity of scattered light depends on the wavelength of incident light ?

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: A Student needs a lens of power -2.0 dioptre to correct his distant vision. The focal length of the given less is :

• a) + 50 cm
• b) - 50 cm
• c) 100 cm
• d) -100 cm

Answer: - 50 cm

Question: Power of accommodation (max, variation in power of eye lens) of a normal eye is about :

• a) 1D
• b) 2D
• c) 3D
• d) 4D

Answer: 4D

Question: Least distance of distinct vision of a long-sighted man is 40 cm. He wish to reduce it to 25 cm by using a lens, the focal of the lens is :

• a)

  

• b)

  

• c) + 200 cm
• d) -200 cm

Answer:

Question: In a compound microscope, magnifying powers of objective and eye lenses are m1 and m2 respectively. The magnifying power of the microscope will be :

• a) m1m2
• b) m1 + m2  
• c) m1 - m2       
• d)

  

Answer:    m1m2

Question: A compound microscope has an objective of focal length 0.5 cm and an eyepiece of focal length 2.5 cm. If its tube length is 25 cm. Calculate what will be the magnifying power of the microscope.

• a) 500
• b) 400
• c) 300
• d) 200

Answer: 500

Question: The focal length of eye lens and object lens of a telescope is 4 mm and 4cm respectively. If final image of an far object is at ∞. Then the magnifying power and length of the tube are :

• a) 10, 4.4 cm
• b) 4, 44 cm
• c) 44, 10 cm
• d) 10, 44 cm

Answer: 10, 4.4 cm

Question: The defect of vision in which person can seen distant objects clearly but nearly object looks blurred is :

• a) Myopia
• b) Astigmatism
• c) Hypermetropia
• d) Presbyopia

Answer: Hypermetropia