brodidit for students
بصری آلات
گیارہویں جماعت · طبیعیات · 8 سوالات
نام: ____________________ تاریخ: ____________
The magnifying power of a simple microscope for a near point of 25 cm and focal length 5 cm is (image at the near point):
- A 5
- B 25
- C 30
- D 6
A telescope's magnifying power (normal adjustment) is:
- A f objective x f eyepiece
- B f objective - f eyepiece
- C f eyepiece / f objective
- D f objective / f eyepiece
The human eye forms its image on the:
- A Cornea
- B Pupil
- C Retina
- D Iris
Short sight is corrected with a:
- A Concave lens
- B Plane mirror
- C Convex lens
- D Prism
In an optical fibre, light travels by:
- A Diffraction
- B Refraction only
- C Total internal reflection
- D Dispersion
A compound microscope has:
- A Three prisms
- B One concave lens
- C A plane mirror only
- D Two convex lenses
The near point of a normal eye is about:
- A 1 m
- B 1 cm
- C 10 m
- D 25 cm
Long sight can be corrected using:
- A A plane glass
- B A concave lens
- C A prism
- D A convex lens
جوابی کلید
1. D, 2. D, 3. C, 4. A, 5. C, 6. D, 7. D, 8. D
M = 1 + D / f = 1 + 25 / 5 = 6.
M = f_o / f_e.
The retina holds the light sensitive cells.
A diverging lens moves the image back onto the retina.
Light is trapped in the core by total internal reflection.
An objective and an eyepiece.
The least distance of distinct vision is about 25 cm.
A converging lens brings the image forward.