Tuesday, November 22, 2011
Class X Physics Chapter: Light-Reflection and Refraction Quiz Questions
Q1. Why do we prefer a convex mirror as a rear-view mirror in vehicles?
Q2. Name the mirror that can give an erect and enlarged image of an object?
Q3. 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?
Q4. Is the optical centre always at the centre of lens?
Q5. When the image formed is virtual and erect, what is the magnification, positive or negative?
Q6. When the image formed is real and inverted, what is the magnification, positive or negative?
Q7. Is mirror formula valid only for the plane mirror?
Q8. Which light will refract more, a violet or red, if they pass through the same glass slab with the same angle of incident?
Q9. Does Snell’s law fail, if yes than when?
Q10. What is a lens? Answers
A1. Convex mirrors enable the driver to view much larger area than would be possible with a plane mirror.
A2. When an object is placed between the pole and the principal focus of a concave mirror, the image formed is virtual, erect, and enlarged
A3. 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.
A4. No, only if both the curved surfaces are symmetrical, optical centre will be at the centre.
A5. When the image formed is virtual and erect, magnification is positive.
A6. When the image formed is real and inverted magnification is negative.
A7. No, the mirror formula is valid for plane as well as for all spherical mirrors for all positions of the object.
A8. Violet light will refract more than the red light, because its wavelength is less than that of red.
A9. Snell’s law fails when the light rays incident normally on the surface of a refracting medium. In this case light passes undeviated from the surface i.e. no refraction occurs.
A10. 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.