A point object is placed `33cm`froma convex mirror of curvature radius`=40cm`A glass plate of thickness `6cm`and index`2.0` placed between the object and mirror,clsoe to the mirror,Afind the distance of final image form the object?

Answer

`42cm`

Explanation

Shift in object due to refraction by slab=`t(1-(1)/(mu))`
`6(1-(1)/(2))`
`3cm`
For mirror ,position of object `u=-(33-3)`
`-30cm`
`(1)/(v)+(1)/(u)=(2)/(R )`
`(1)/(v')+(1)/(-30)=(2)/(40)`
`(1)/(v')=(1)/(20)+(1)/(30) rArr v'=12cm`
shift in image due to refraction by slab
`=t(1-(1)/(mu))`
`=6(1-(1)/(2))`
`=3 cm`
Distance of image=`(12-3)`
`=9cm`
Distance between `O`and`I`=`33cm+9cmrArr` Distance=42cm
`42cm`