Optical Instruments — Homi Bhabha Class 9 Physics MCQs with Solutions
Free Homi Bhabha Class 9 Physics Optical Instruments MCQs with step-by-step solutions (8 questions). Part of Light & Optics. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Optical Instruments · medium · theory
A simple microscope (magnifying glass) is essentially a:
A. single convex lens of short focal length ✓ Correct
B. convex mirror
C. plane mirror
D. concave lens
Solution: A simple microscope is a short-focal-length convex lens that gives an enlarged virtual image.
Q2 — Optical Instruments · medium · theory
A telescope is an optical instrument used to view:
A. distant objects such as stars and planets ✓ Correct
B. very small nearby objects
C. objects inside the body
D. objects in the dark
Solution: A telescope magnifies far-off objects like celestial bodies.
Q3 — Optical Instruments · hard · theory
A periscope, used in submarines to see above the water, works using:
A. a concave mirror only
B. two plane mirrors (or prisms) inclined at 45° ✓ Correct
C. a prism that disperses light
D. a single convex lens
Solution: Two parallel mirrors at 45° reflect light down the tube, letting the viewer see over obstacles.
Q4 — Optical Instruments · medium · theory
The lens present in the human eye is a:
A. concave lens
B. convex mirror
C. plane glass
D. convex lens ✓ Correct
Solution: The eye lens is convex; it focuses light onto the retina to form a real, inverted image.
Q5 — Optical Instruments · hard · theory
The image formed on the film/sensor of a camera is:
A. virtual and diminished
B. real, erect and magnified
C. virtual, erect and magnified
D. real, inverted and diminished ✓ Correct
Solution: A camera's convex lens forms a real, inverted, diminished image of a distant object on the film/sensor.
Q6 — Optical Instruments · easy · theory
Which optical instrument is used to see distant heavenly bodies such as stars and planets?
A. A kaleidoscope
B. A periscope
C. A telescope ✓ Correct
D. A microscope
Solution: A telescope is designed to view distant objects like stars and planets. A microscope is used for tiny, nearby objects, and a periscope is used to see over or around obstacles.
Q7 — Optical Instruments · medium · theory
A simple microscope (magnifying glass) produces a magnified, erect, virtual image. To do this it uses:
A. A concave lens
B. A single convex lens with the object placed within its focal length ✓ Correct
C. A concave mirror
D. A plane mirror
Solution: A magnifying glass is a single convex lens. When the object is kept within the focal length, the lens forms a magnified, erect and virtual image, which is exactly what a simple microscope does.
Q8 — Optical Instruments · hard · theory
In a compound microscope, both lenses are convex. The objective lens first forms which kind of image, that the eyepiece then further enlarges?
A. A real, inverted and magnified image ✓ Correct
B. A diminished real image at its focus
C. No image at all
D. A virtual, erect image
Solution: The objective forms a real, inverted, magnified image of the object. The eyepiece then acts like a simple microscope, treating this image as its object and magnifying it further into a large virtual image seen by the eye.