Light reflection and refraction Worksheet6

Focal length of a convex mirror is 50 cm. What is its radius of curvature ?

Radius of a concave mirror is 25 cm. What is the magnification produced ?

A concave mirror produces 10 cm long image of an object 2 cm. What is the magnification produced ?

An object 1 cm high is held near a concave mirror of magnification 10. How tall will be the image ?

Find the size, nature and position of image. Formed by a concave mirror, when an object of size 1 cm is placed at a distance of 15 cm. Given focal length of mirror is 10 cm.

An object 2 cm high is placed at a distance of 16 cm from a concave mirror, which produces 3 cm high inverted image. What is the focal length of the mirror ? Also, find the position of the image.

An erect image 3 times the size of the object is obtained with a concave mirror of radius of curvature 36 cm. What is the position of the object?

A 2.5 cm candle is placed 12 cm away from a convex mirror of focal length 30 cm. Give the location of the image and the magnification.

An object is placed in front of a concave mirror of focal length 20 cm. The image formed is three times the size of the object. Calculate two possible distances of the object from the mirror ?

A concave mirror produces a real image 10 mm tall, of an object 2.5 mm tall placed at 5 cm from the mirror. Calculate focal length of the mirror and the position of the image ?
Answer:

Here, f = cm, R = ?
From R = 2 f = 2 × 50 = 100 cm.

Here, R = 25 cm, f = ?
From f =12.5 cm.


Here, h_{1} = 1 cm, h_{2} = ? m = ± 10
From m =
.

As
∴
ν = –30 cm
Negative sign of ν shows that the image is real.
As
h_{2} = –2 cm
Negative sign of h_{2} shows that the image is real and inverted.

Here,
h_{1} = 2cm, u = –16cm, h_{1} = –3cm
f = ? v = ?
As
v = –24 cm.
As
= –9.6cm.

Here, m = 3, R = –36 cm, u = ?
As m = 3 = or v = –3 u
As
3 u = –36, u = –12

Here, h_{1} = 2.5 cm, u = –12 cm
f = 30 cm, v = ?, m = ?
As
= = 8.6 cm.
Positive sing of v shows that the image is virtual.
or
h_{2} = 1.7 cm

–40/3 or –80/3 cm
m = ±3.

Here h_{2} = –10mm, h_{1} = 2.5 mm
u = –5cm, f = ?, v = ?
As or v = –20 cm
Negative sign of shows that image is real.
–4 cm.