Question: 2. Name the mirror that can give an erect and enlarged image of an object?
Question: 3. What could be the position of the object if the image formed by a concave mirror is observed
to be virtual, erect and larger than the object?
Question: 4. Is the optical centre always at the centre of lens?
Question: 5. When the image formed is virtual and erect, what is the magnification, positive or negative?
Question: 6. When the image formed is real and inverted, what is the magnification, positive or negative?
Question: 7. Is mirror formula valid only for the plane mirror?
Question: 8. Which light will refract more, a violet or red, if they pass through the same glass slab with the
same angle of incident?
Question: 9. Does Snell’s law fail, if yes than when?
Question: 10. What is a lens?
Answers for above Questions
Answer: 1. Convex mirrors enable the driver to view much larger area than would be possible with a plane
Answer : 2. When an object is placed between the pole and the principal focus of a concave mirror, the
image formed is virtual, erect, and enlarged
Answer: 3. If the image formed by a concave mirror is virtual, erect and larger than the object, the position
of the object should be between the pole of the mirror and its principal focus.
Answer: 4. No, only if both the curved surfaces are symmetrical, optical centre will be at the centre.
Answer: 5. When the image formed is virtual and erect, magnification is positive.
Answer: 6. When the image formed is real and inverted magnification is negative.
Answer: 7. No, the mirror formula is valid for plane as well as for all spherical mirrors for all positions of
Answer: 8. Violet light will refract more than the red light, because its wavelength is less than that of red.
Answer: 9. Snell’s law fails when the light rays incident normally on the surface of a refracting medium. In
this case light passes un deviated from the surface i.e. no refraction occurs.
Answer: 10. A lens is a portion of a transparent refracting medium bounded by two spherical surfaces,
generally spherical or cylindrical or one curved and one plane surface. It has a perfect or approximate axial
symmetry which transmits and refracts light.
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