11th class (Fsc) Physics unit 10 MCQs
chapter 10 MCQs 11th Class Physics
Optical Instruments:
1. The least distance of distinct vision for the normal eye is:
a. 125cm
b. 15cm
c. 25m
d. 25cm
2. The minimum distance from the eye at which an object appears to be distinct is:
a. 25cm
b. 15cm
c. 30cm
d. 20cm
3. The ability to reveal the minor details of an object under examination is called:
a. Scattering
b. Resolving power
c. Reflection
d. Magnification
4. Rayleigh formula for resolving power:
a. R = D/1.22λ
b. R = 1.22λ/D
c. R = λ/1.22D
d. R = 1.22D/λ
5. The formula 𝛼min = 1.22 λ/D for resolving power of lens was given by:
a. Young
b. Newton
c. Rayleigh
d. Michelson
6. If the object is at 5cm from the lens of simple microscope than its magnifying power will be:
a. 20
b. 5
c. 25
d. 10
7. A convex lens acts as diverging lens if the objects is placed at:
a. Between F and 2F
b. F
c. Within the F
d. 2F
8. The magnifying power of simple microscope is:
a. 1 – d/p
b. 1 + d/q
c. 1 + d/f
d. 1 – d/q
9. If a convex lens of focal length 5cm is used as simple microscope then its magnifying power will be:
a. 10
b. 5
c. 25
d. 6
10. The magnifying power of magnifying glass is 3, then focal length will be:
a. 5cm
b. 25cm
c. 3cm
d. 12.5cm
11. The magnifying power if a convex lens of focal length 10cm is:
a. 11
b. 7
c. 3.5
d. 9.6
12. The focal length of convex lens is:
a. Large
b. Negative
c. small
d. Positive
13. Magnificent of convex lens is:
a. 1 + f/d
b. 1 + d/f
c. 1 – f/d
d. 1 – d/f
14. If an object is placed in between focus point and optical canter of a convex lens, the image formed by lens is:
a. Virtual inverted
b. Real inverted
c. Virtual erected
d. Virtual diminished
15. The final image formed by a simple microscope is:
a. Infrared light
b. Virtual and inverted
c. White light
d. Virtual and erect
16. The resolving power of a compound microscope depends on:
a. The diameter of the eyepiece
b. Length of the microscope
c. The position of an observer’s eye with regard to the eye lens
d. The diameter of the objective lens
17. If a convex lens is used as a magnifying glass, which lens will give higher magnification that has:
a. Large size
b. Short size
c. Short focal length
d. Long focal length
18. The resolving power of an astronomical telescope depends on:
a. The focal length of the eye lens
b. The focal length of the objective lens
c. The diameter of the objective lens
d. The least distance of distinct vision of the observer
19. The units of magnifying power of microscope of telescope are:
a. Diopter
b. Meter
c. No unit
d. m-1
20. For normal adjustment, the length of astronomical telescope is:
a. fo + fe
b. fo – fe
c. fo /fe
d. fo fe
21. The final image seen through eye-piece in telescope is;
a. Virtual, enlarge and inverted
b. Real, enlarge and inverted
c. Real, enlarge and erect
d. Virtual, enlarge and erect
22. If an object lies at focus point F in front of a convex lens, its image is formed at:
a. 3F
b. 2F
c. Infinity
d. F
23. Magnifying power of astronomical telescope is:
a. fefo
b. fe/fo
c. 1/fefo
d. fo/fe
24. If focal length of objective and eye piece is 0.5m and 10cm respectively then magnifying power of telescope will be:
a. 10
b. 5
c. 20
d. 0.5
25. The final image obtained by astronomical telescope is:
a. Magnified
b. Erect
c. Virtual
d. All of these