If the correct time of exposure is 200 1 sec with a lens camera f : 2.8 , what would be correct time of exposure with a lens camera f : 5.6 ?

Exposure time ∝ ( f -number ) 2 . t = ( 1/200 ) × ( 5.6/2.8 ) 2 = 4/200 = 0.02 sec . (No printed key - proposed.)

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Physics - Geometrical Optics Question with Solution | TestHub

PhysicsGeometrical OpticsOptical instrumentsMedium2 minQB

PhysicsMediumsingle choice

If the correct time of exposure is $\frac{1}{200}$ sec with a lens camera $f : 2.8$ , what would be correct time of exposure with a lens camera $f : 5.6 ?$

Options:

Answer:

Solution:

Exposure time $\propto (f -number)^{2}$ .

$t = (1/200) \times (5.6/2.8)^{2} = 4/200 = 0.02 sec .$

(No printed key - proposed.)

Stream:JEESubject:PhysicsTopic:Geometrical OpticsSubtopic:Optical instruments

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