Ray-Optics-And-Optical-Instruments-Quiz-7

Ray Optics And Optical Instruments Quiz-7

Dear Readers,

As per analysis for previous years, it has been observed that students preparing for NEET find Physics out of all the sections to be complex to handle and the majority of them are not able to comprehend the reason behind it. This problem arises especially because these aspirants appearing for the examination are more inclined to have a keen interest in Biology due to their medical background. 

Furthermore, sections such as Physics are dominantly based on theories, laws, numerical in comparison to a section of Biology which is more of fact-based, life sciences, and includes substantial explanations. By using the table given below, you easily and directly access to the topics and respective links of MCQs. Moreover, to make learning smooth and efficient, all the questions come with their supportive solutions to make utilization of time even more productive. Students will be covered for all their studies as the topics are available from basics to even the most advanced. 

Q61. A man can see the object between 15 cm and 30 cm. He uses the lens to see the far objects. Then due to the lens used, the near point will be at

•  10/3 cm
•  30 cm
•  15 cm
•  100/3 cm

Solution
                                 

Q62.A normally incident ray reflected at an angle of 90°. The value of critical angle is

•  45°
•  90°
•  65°
•  43.2°

Solution
Critical angle C is equal to incident angle if ray reflected normally ∴C=90°

Q63.  A ray of light is incident at 50° on the middle of one of the two mirrors arranged at an angle of 60° between them. The ray then touches the second mirror, gets reflected back to the first mirror, making an angle of incidence

•  50°
•  60°
•  70°
•  80°

Solution
70°

Q64. Glass has refractive index μ with respect to air and the critical angle for a ray of light going from glass to air is θ. If a ray of light is incident from air on the glass with angle of incidence θ, the corresponding angle of refraction is

•  sin^-1(1/√μ)
•  90°
•  sin^-1⁡(1/μ² )
•  sin^-1⁡(1/μ)

Solution
                         

 

Q65.A leaf which contains only green pigments, is illuminated by a laser light of wavelength 0.632 μm. It would appear to be

•  Brown
•  Red
•  Black
•  Green

Solution
  Given wavelength does not belong to green therefore all light will be absorbed

Q66. The focal length of the objective and the eye-piece of a microscope are 4 mm and 25 mm respectively. If the final image is formed at infinity and the length of the tube is 16 cm, then the magnifying power of microscope will be

•  -337.5
•  -3.75
• 3.375
•  33.75

Solution
                          

Q67.A microscope is focused on a coin lying at the bottom of a beaker. The microscope is now raised up by 1 cm. To what depth should the water be poured into the beaker so that coin is again in focus? (Refractive index of water is 4/3)

•  1 cm
•  3 cm
•  4/3 cm
•  4 cm

Solution
Suppose water is poured up to the height h, So h(1-1/μ)=1⇒h=4 cm

Q68.As shown in figure position of an images I of an object O formed by lens. This is possible if

•  A convex lens is placed to the left of O
•  A concave lens is placed to the left of O
•  A convex lens is placed between O and I
•  A concave lens is placed to the right of I

Solution
Diminished erect image is produced only by a concave lens

Q69.The hyper-metropia is a

•  Short-side defect
•  Long-side defect
•  Bad vision due to old age
•  None of these

Solution
Long-side defect

Q70. An object is placed 30 cm to the left of a diverging lens whose focal length is of magnitude 20 cm. Which one of the following correctly states the nature and position of the virtual image formed? Nature of image Distance from lens

•  Inverted, enlarged 60 cm to the right
•  Erect, diminished 12 cm to the left
•  Inverted, enlarged 60 cm to the left
• Erect, diminished 12 cm to the right

Solution