What is the phenomenon one encounters when a lens fails to converge all the wavelength of light on a single focal plane? Vignetting effect Chromatic aberration Non-collinear vanishing points Distorted image

When a beam of white light is allowed to pass through convex lens parallel to principal axis, the different colours of light converge at different point on the principle axis after refraction. This is called :ScatteringChromatic aberration Spherical aberrationPolarisation

The spherical aberration of a converging lens can be corrected by reducing the thickness of the lens periphery.  The spherical aberration of the lens is caused because light rays emerging from the lens:A.are insufficiently refracted at the lens periphery.B.converge at the lens focal point uniformly.C.are excessively refracted at the lens periphery.D.are scattered due to chromatic dispersion.

The phenomenon of “chromatic aberration” leads to

What is another name for a convex lens?A concave lensA converging lensA diverging lensA negative lens2What will happen to parallel rays of light which strike a convex lens?They will converge upon exiting the lensThey will still be parallel upon exiting the lensThey will diverge upon exiting the lensIt is impossible to say without knowing the exact shape of the lens3What will happen to parallel rays of light which strike a concave lens?They will diverge upon exiting the lensThey will converge upon exiting the lensThey will still be parallel upon exiting the lensIt is impossible to say without knowing the exact shape of the lens4A convex lens has a focal length of 30 cm.  In which of the following cases will a real image NOT be produced?When an object is placed 80 cm from the lensWhen an object is placed 60 cm from the lensWhen an object is placed 20 cm from the lensWhen an object is placed 40 cm from the lens5The focal length of a convex lens is 10 cm.  An object is placed 15 cm from the lens.  Which of the following describes the image which will be produced of this object?Real, inverted and diminishedReal, inverted and magnifiedVirtual, inverted and diminishedVirtual, upright and magnified6Lenses work as a result of which of the following processes?ReflectionRarefactionReflationRefraction

A convex lens is dipped in a liquid whose refractive index is equal to the refractive index of the lens. Then its focal length willbecome infinitebecome small, but non- zeroremain unchangedbecome zero