Ray Optics and Optical Instruments - Online Test
Q1. Accommodation of the human eye is
Answer : Option C
Explaination / Solution:
No Explaination.
Q2. Farsighted or hypermetropic eye can be corrected by
Answer : Option D
Explaination / Solution:
No Explaination.
Q3. A plano-convex lens is made of glass of refractive index 1.5. The focal length f of the lens & the radius of curvature R of its curved surface, are related by
Answer : Option A
Explaination / Solution:
No Explaination.
Q4. A Plano convex lens of curvature of 30 cm & R.I. 1.5, produces a real image of an object kept 90cm from it. The magnification is
Answer : Option B
Explaination / Solution:
No Explaination.
Q5. An equi-convex thin lens (μ =1.5) of focal length in air as 30cm is sealed into an opening in one end of tank filled with water ((μ =1.33). At the end of the tank opposite the lens is a plane mirror, 80 cm distant from the lens. The position of the image formed by the lens-water-mirror system of a small object outside the tank on the lens axis and 90cm to the left of the lens will be
Answer : Option D
Explaination / Solution:
No Explaination.
Q6. When an astronomical telescope is focused on a distant star, the distance of the eye piece from the objective is 60 cm. When focused on a distant flag post the eye piece must be drawn at 0.1cm. If the focal length of the eye piece is 5cm; what will be the distance of the pole from the objective? Assume that the eye is focused for infinity?
Answer : Option B
Explaination / Solution:
No Explaination.
Q7. When a lens is inserted between an object & the screen which are at fixed distance apart, the size of the image is either 6cm or 2/3 cm. The size of the object is
Answer : Option A
Explaination / Solution:
No Explaination.
Q8. A far-sighted man who has lost his spectacles reads a book by looking through a small hole in the sheet of paper. Then
Answer : Option B
Explaination / Solution:
No Explaination.
Q9. The graph drawn with object distance along abscissa & image as ordinate for a convex lens is
Answer : Option B
Explaination / Solution:
No Explaination.
Q10. Binoculars is preferred to a terrestrial telescope to observe a cricket match, because
Answer : Option A
Explaination / Solution:
No Explaination.
