351. Image of an object 5 mm high is only 1 cm high. Magnification produced by lens is__________________?
352. A convex lens gives a virtual image only when the objects lies_________________?
A. between principal focus and center of curvature
B. beyond 2 f
C. at the principal focus
D. between principal focus and optical center
353. The minimum distance between an object and its real image in a convex lens is_____________?
A. 2 f
B. 2.5 f
354. Dioptre power of an concave lens of 10 cm focal length is_______________?
A. 10 dioptre
B. 10 dioptre
C. 1 / 10 dioptre
D. 1 / 10 dioptre
355. A point where the incident parallel rays of light converge or appear to diverge after passing through a lens is called______________?
A. center of curvature
C. optical center
356. The value of critical angle for glass is_______________?
357. In optic fiber transmission system _____________ are used regenerate the dim light signal?
358. Magnification of the astronomical telescope is_____________?
359. 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
360. 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