Question

Hold a concave mirror in our hand and direct its reflecting surface to the sun. Direct the light reflected by the mirror on to a sheet of paper held close to the mirror. Move the sheet of paper back and forth gradually until the paper sheet find a sharp spot of light. Holding the mirror and the paper in the same position for a few minutes produces a burn producing smoke. 1.1) The distance between the paper sheet and the concave miror gives an ldea of rough measurement of
a) Aperture
b) Focal lengtn
c) Radius of curvature
d) None of the above
1.2). A concave mirror of focal length 15 cm forms an image having8 twice the linear dimensions of the object. The positlon of the object, when the image is virtual, will be
a) 22.5 cm
b} 7.5 cm
c) 30 cm
d) 45 cm
1.3). Which of the following does not describe a ray that can be drawn for a concave mirror? a) An incident ray through the mirror's Centre, reflecting right back through the Centre.
b) An incident ray through the Centre point, reflecting right back

through the focal point.

c) An incident ray through the focal point, reflecting parallel to the

principal axis

d) An incident ray parallel to the principal axis, reflecting through the

focal point.

14) A concave mirror of radius of 30 cm is placed in water. Its focal

length in air and water differ by

a) 15 cm b) 20cm c) 30 cm d) 0cm.

1.5) An object is placed at 10 cm in front of a concave mirror of radius

of curvature 15cm, Position of the image, nature and magnification of

the image s

a) Image distance= 30 cm from the mirror on the same side as the

object, nature is real and inverted and magnified

b) Image distance= 30 cm from the mirror on the other side as the

object, nature is virtual and erect and magnified

c) Image distance= 30 cm from the mirror on the same side as the

object, nature is real and inverted and diminished

d) Image distance= 30 cm from the mirror on the same side as the

object, nature is real and erect and magnified.​

Answer 1

Answer:

(d) option is correct I think