Question

A student dud an experiment with a convex lens.he put an object at different distances 25cm,30cm,40cm,60cm,and 120cm from the lens.in each case he measured the distance of the image from the lens.his results were100cm,24cm,60cm30cm,40cm respectively.unfortunately his results are written in wrong order.what would be the image distance if the object distance was 90cm? give answer​

Answer 1

The image distance which will be in correct order will be 100cm, 60cm , 40cm,

30cm, 24cm.

While, we know that when u= -25cm and v=100cm.

The equation 1/v - 1/u = 1/f. So, on substituting the values from the given question we will get that 1/100 - 1/(-25) = 1/f which on solving we will get the value of f to be 20cm.

Now when u = -90cm.

1/v - 1/u = 1/f.

1/v - 1/(-90) = 1/20.

Which on solving we will get the value of v to be 25.7 cm.

So, the object distance which give the biggest image is 25cm and the focal length of lense is 20cm.

HOPE THAT MY ANSWER HELPS

Answer 2

Answer:

! the object distance which give the biggest image is 25 cm and focal length of lense is 20 cm