In multimode step index fibre the refractive index of core and cladding is____________?
(A) same
(B) different
(C) zero
(D) different with refractive index of core higher than cladding
A convex lens of focal length f1 and a concave lens of focal length f2 are placed in contact. The focal length of the combination is_____________?
(A) f2 + f1
(B) f2 – f1
(C) f1f2/f2+f1
(D) f1f2/f1-f2
If a convex lens of large aperture fails to converge the light rays incident on it to a single point, it is said to suffer from______________?
(A) chromatic aberration
(B) spherical aberration
(C) both spherical and chromatic
(D) distortion
The least distance of distinct vision for a normal eye is_______________?
(A) 15 cm
(B) 25 cm
(C) 30 cm
(D) 40 cm
Magnifying power of simple microscope______________?
(A) increase with increase in focal length
(B) increase with decrease in focal length
(C) no effect with decrease or increase with focal length
(D) list distance of distinct vision
If an object is placed away from 2f of a converging lens then the image will be_______________?
(A) real and erect
(B) virtual and erect
(C) real and inverted
(D) virtual
The function of collimeter in spectrometer is________________?
(A) to produce parallel beams of light
(B) to filter the light rays
(C) to make them
(D) no function
Errors in the transmission of power through optic fiber can be minimized by using a______________?
(A) Multimode index fiber
(B) Graded index fiber
(C) Single mode step index fiber
(D) Copper wire
Magnification of the astronomical telescope is_____________?
(A) fo+fe
(B) fo/fe
(C) fe/fo
(D) (1+fo/fe)L/fo
In optic fiber transmission system _____________ are used regenerate the dim light signal?
(A) Diodes
(B) Repeaters
(C) Laser
(D) Transformer