351. Image of an object 5 mm high is only 1 cm high. Magnification produced by lens is__________________?
A. 0.5
B. 0.2
C. 1
D. 2

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
C. 3f
D. 4f

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
B. focus
C. optical center
D. aperture

356. The value of critical angle for glass is_______________?
A. 42°
B. 47°
C. 52°
D. 50°

357. In optic fiber transmission system _____________ are used regenerate the dim light signal?
A. Diodes
B. Repeaters
C. Laser
D. Transformer

358. Magnification of the astronomical telescope is_____________?
A. fo+fe
B. fo/fe
C. fe/fo
D. (1+fo/fe)L/fo

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