At what distance from a screen will a 27 Cd lamp provide the same illumination as a 75 Cd lamp 15 m from the screen?

May 2, 2022

50 Views

At what distance from a screen will a 27 Cd lamp provide the same illumination as a 75 Cd lamp 15 m from the screen?

Q. At what distance from a screen will a 27 Cd lamp provide the same illumination as a 75 Cd lamp 15 m from the screen?

A. 9 m

B. 6 m

C. 3 m

D. 1 m

Answer: 9 m

At what distance from a screen will a 27 Cd lamp provide the same illumination as a 75 Cd lamp 15 m from the screen?

Previous

In an astronomical telescope the focal length of objective lens is 100 cm and that of eyepiece is 2 cm. The magnifying power of the telescope for the normal eye is

At what distance from a screen will a 27 Cd lamp provide the same illumination as a 75 Cd lamp 15 m from the screen?

Next

Monochromatic light of frequency 5 x 10⁴ Hz travelling in vacuum enters a medium of refractive index 1.5. Its wavelength in the medium is :

Related Articles

A man runs towards the plane mirror at 2 m/s. The relative speed of his image with respect to him will be

A man runs towards the plane mirror at 2 m/s. The relative speed of his image with respect to him will be

A concave lens from the image of an object which is

A concave lens from the image of an object which is

Which of the given is NOT paired correctly?

Which of the given is NOT paired correctly?

If a diverging lens is to be used to form an image which is one fourth of the size of the object where must the object be placed?

If a diverging lens is to be used to form an image which is one fourth of the size of the object where must the object be placed?

We will be happy to hear your thoughts

Leave a reply Cancel reply

You must be logged in to post a comment.