 # Optical Instruments MCQs

For your better entry test preparation and better Physics MCQs preparation, in this section, we are going to post Optical Instruments MCQs. Optical instruments are the devices which process light wave to enhance an image for a more clear view. Use of an optical instrument, such as a magnifying lens or any complicated device like a microscope or telescope usually makes things bigger and helps us to see in a more detailed manner.

### Optical Instruments MCQs

1. 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

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. The diameter of a lens is called
A. Focal length
B. Principal axis
C. Aperture

4. In going form a denser to rarer medium a ray of light is
A. Deviated
B. Bent away from the normal
C. Bent towards the normal
D. Polarized

5. Unit of the power of a lens is
A. Meter
B. Watt
C. Dioptre
D. Horsepower

6. Dioptre power of a concave lens of 10 cm focal length is
A. 10 dioptre
B. 10 dioptre
C. 1 / 10 dioptre
D. 1 / 10 dioptre

7. The power of a concave lens is
A. Real
B. Virtual
C. Positive
D. Negative

8. 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

9. 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