a magnifying glass of focal lens 5cm is used to magnify small objects held 4cm from optical centre of lens. determine position and magnification of image

Answer 1

To determine the position and magnification of the image, we can use the lens formula:

1/f = 1/v + 1/u

where:
f = focal length of the lens = 5 cm
v = image distance
u = object distance = 4 cm

Substitute the given values into the formula:

1/5 = 1/v + 1/4

Solving for v:

1/v = 1/5 - 1/4
1/v = (4 - 5) / 20
1/v = -1 / 20
v = -20 cm

Since the image distance is negative, the image is formed on the same side as the object (which is opposite to the direction of the incident light). Therefore, the image is virtual.

Next, let's calculate the magnification (M):

M = -v / u
M = -(-20) / 4
M = 5

The negative sign indicates that the image is inverted relative to the object. Therefore, the image is formed 20 cm from the lens on the same side as the object, and the magnification is 5.