List of top Physics Questions on spherical lenses asked in KEAM

If a thin lens of focal length 20 cm is in contact with another lens of power 4 D, then the effective power of the combination is

A convex lens of focal length 20 cm is placed in contact with a concave lens of focal length 40 cm. The power of the combination is

An object is placed at a distance of 30 cm from a convex lens of focal length 100 cm when it moves 5 cm towards the lens how much is the image being shifted?

An effective power of a combination of 5 identical convex lens having focal length f= 20 cm is

A circular loop is made from a wire of length 6m. If 2A current passes through the circular loop, what is the magnetic moment of the loop?

An optician prescribes a lens of power +2.5 D. The focal length of the lens in water is (Indices: Lens = 1.5, Water = 1.33):

The magnification of an image by a convex lens is positive only when the object is placed

If the radius of curvature of the curved surface of a plano-convex lens is $50$ cm, its focal length is ($\mu = 1.5$)

The magnification of an image by a convex lens is positive only when the object is placed

The position of final image formed by the given lens combination from the third lens will be at a distance of [ $ {{f}_{1}}=+10\text{ }cm, $ $ {{f}_{2}}=-10cm, $ $ {{f}_{3}}=+30\text{ }cm $ ]

The least distance of distinct vision of a person is $75\, cm$. The focal length of the reading spectacles for such a person should be