List of top Physics Questions on Optical Instruments asked in KEAM

Two convex lenses of different focal lengths are in contact with each other. If the focal length of each lens is doubled, the focal power of the combination

The magnifying power of a simple microscope can be increased by using

The simple microscope having a lens of focal length 5 cm gives the magnification of (least distance of distinct vision \(= 25\) cm)

When an object is viewed with a light of wavelength \( 6000 \,\text{\AA} \) under a microscope its resolving power is \( 10^4 \). The resolving power of the microscope when the same object is viewed with a light of wavelength \( 4000 \,\text{\AA} \) is