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?

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

Gkseries: Gkseries.com is a premier website to provide complete solution for online preparation of different competitive exams like UPSC, SBI PO, SBI clerical, PCS, IPS, IAS, IBPS PO, IBPS Clerical exam etc. & other graduate and post-graduate exams. Learn more on about us page