Question

A Galilean telescope adjusted for a relaxed eye is 36.2 cm long. If the objective lens has a focal length of 39.5 cm , what is the magnification

Answer 1

The magnification is
`m = 12`

Step-by-step explanation:

From the question we are told that

The object distance is
`u = 36.2 \ cm`

The focal length is
`v = 39.5 \ cm`

From the lens equation we have that

`(1)/(f) = (1)/(u) + (1)/(v)`

=>
`(1)/(v) = (1)/(f) - (1)/(u)`

substituting values

`(1)/(v) = (1)/(39.5) - (1)/(36.2)`

`(1)/(v) = -0.0023`

=>
`v = (1)/(0.0023)`

=>
`v =-433.3 \ cm`

The magnification is mathematically represented as

`m =- (v)/(u)`

substituting values

`m =- (-433.3)/(36.2)`

`m = 12`