Multiple choice questions of Chapter 10 of Physics for First Year.

1. The least distance of distict vision for a normal eye is:
a) 15 cm
b) 25 cm
c) 30 cm
d) 40 cm

2. 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 centre
d) Aperture

3. A lens which converges a beam of parallel rays to a point is called:
a) Diverging (or concave) lens
b) Converging (or convex) lens
c) Plano concave lens
d) Plano convex lens

4. A real object placed inside the focus of a convex lens gives:
a) Real image but diminished
b) Real image but enlarge
c) Virtual image but diminished
d) Virtual image but enlarge

5. The power of the lens is measured in:
a) Watt
b) Joule
c) Diopter
d) Minutes

6. If a single convex lens is placed close to the eye, it can be used as a
a) Telescope
b) Simple microscope
c) Compound microscope
d) Refracting telescope

7. For the phenominon of total internal reflection, the angle of incidance should be:
a) Equal to critical angle
b) Smaller than critical angle
c) Greater than critical angle
d) Zero

8. The instrument which is used to measure speed of light was developed by
a) Newton
b) Galileo
c) Michelson
d) Graham Bell
e) Huygen

9. In going form a denser to rarer medium a array of light is
a) Un-deviated
b) Bent away from the normal
c) Bent towards the normal
d) Polarized

10. At some angle of incidence, when angle of refraction becomes 90°, this angle is called:
a) Phase angle
b) Incident angle
c) Refractive angle
d) Critical angle

11. 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

12. Dispersion effect may produced error in light signals. This type of error is minimum in:
a) Single mode step index fiber
b) Multimode step index fiber
d) Monomode step index fiber

13. Light signals passes through multimode graded fiber due to:
a) Continuous refraction
b) Total internal reflection
c) Both continuous refraction and total internal reflection
d) Diffraction

14. Critical angle is that incident angle in denser medium for which angle of refraction is.
a) 0o
b) 45 o
c) 90 o
d) 180 o

15. The electrical signals change into light signals for transmission through optical fiber. A light pulse represents.
a) Zero (0)
b) One (1)
c) Both zero (0) and one (1)
d) Neither zero (0) nor one (1)

16. The optical fiber in which the central core has higher refractive index and its density gradually decreases towards its periphery is called:
a) Single mode index fiber
b) Multi mode index fiber
c) Multi mode graded index fiber
d) None of these

17. Which of the phenomenon of light is used in propagation of light through optical fibers?
a) Total internal reflection
b) Polarization
c) Interference
d) Diffraction