$A$ diverging lens of focal length $10 \, cm$ is placed $10 \, cm$ in front of a plane mirror as shown in the figure. Light from a very far away source falls on the lens. The final image is at a distance

Which of the following can form a diminished,virtual,and erect image of your face?

The dispersive power of the material of a lens of focal length $20 \; cm$ is $0.08$. The longitudinal chromatic aberration of the lens is ...... $cm$.

The exposure time of a camera lens at the $f/2.8$ setting is $1/200$ second. The correct time of exposure at $f/5.6$ is......$sec$

$A$ lamp is hanging at a height of $4\,m$ above a table. The lamp is lowered by $1\,m$. The percentage increase in illuminance will be.....$\%$

$A$ fish in an aquarium,$30 \, cm$ deep in water,can see a light bulb kept $50 \, cm$ above the surface of water. The fish can also see the image of this bulb in the reflecting bottom surface of the aquarium. The total depth of water is $60 \, cm$. Then the apparent distance between the two images seen by the fish is $(\mu_w = 4/3)$.