## Physics MCQ on Photometry for NEET, JEE, Medical and Engineering Exam 2021

MCQ on Photometry: Previous trends reveal that NEET/JEE aspirants find Physics as the most challenging section amongst the other sections. But most of them fail to decipher the reason behind this. This particularly can be as the candidates taking up this examination are predominantly medical aspirants with their subject of interest being Biology. Also, sections like Physics are more on theories, laws, numerical as opposed to Biology which is more of fact-based, life sciences and comprising of substantial explanations.

In this post we are providing you MCQ on Photometry, which will be beneficial for you in upcoming NEET, AIIMS, JEE, WBJEE, Medical and Engineering Exams.

## MCQ on Photometry

Q1. Which of the following has more luminous efficiency?
a) 40 W fluorescent tube
b) 40 W bulb
c) Both have the same luminous efficiency
d) Cannot say

(a) 40 W fluorescent tube

Q2. Lux is equivalent to which of the following?
a) 1 candela/m2
b) 1 lumen/cm2
c) 1 lumen/m2
d) 1 candela/cm2

(a) 1 candela/m2

Q3. Venus looks brighter than other stars because _______.
a) it has no atmosphere
b) atomic fission occurs on its surface
c) it has a higher density than other stars
d) it is closer to earth than most stars

(d) it is closer to earth than most stars

Q4. In a movie hall, if the distance between the screen and the projector is increased by 1% what happens to the illumination on the screen?
a) Increases by 1%
b) Decreases by 1%
c) Increases by 2%
d) Decreases by 2%

(d) Decreases by 2%

Q5. The distance between a point source of light and a screen is 60 cm and now this distance is increased to 180 cm. By how many fractions will the intensity on the screen change as compared to the original intensity?
a) 9 times
b) 3 times
c) (1/9) times
d) (1/3) times

(c) (1/9) times

Q6. Which of the following sources of light is the inverse square law valid for?
a) Cylindrical source
b) Searchlight
c) Isotropic point source
d) All types of light sources

(c) Isotropic point source

Q7. Lux is a unit of which of the following?
a) Illuminance on a surface
b) Luminous intensity of a source
c) Luminous efficiency of the source of light
d) Transmission coefficient of a surface

(a) Illuminance on a surface

Q8. If a lamp has a luminous efficiency of Five lumen/watt and a luminous intensity of 35 candela. What is the power of the lamp?
a) 176 W
b) 88 W
c) 36 W
d) 80 W

(b) 88W

Q9. What is the power of the lamp if its luminous efficiency is 2 lumen/watt and its luminous intensity is 42 candela?
a) 62 W
b) 74 W
c) 138 W
d) 264 W

(d) 264 W

Q10. A point source of 100 candela is held 5 m above a sheet of blotting paper which reflects 75% of the incident light. What is the illuminance of blotting paper?
a) 4 lux
b) 4 phot
c) 3 lux
d) 3 phot

(a) 4 lux