Home 1st Year Physics Notes FSC 1st Year Physics Chapter 10 Exercise & Numericals Notes

# FSC 1st Year Physics Chapter 10 Exercise & Numericals Notes

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In this post, I am sharing FSC 1st Year Physics Chapter 10 Solved Exercise & Numericals Notes PDF Download for the students of Intermediate Part 1. Optical Instruments is the 10th Chapter in FSC First Year Book. Students can download the 11th class physics chapter 10 Solved Exercise & Numericals Notes PDF on their laptops or mobiles. This is a tinny file of 9 pages only. These Physics Notes for Class 11 are for all the boards working under Punjab Board like Gujranwala Board, Lahore Board, Faisalabad Board, Multan Board, Rawalpindi Board, Sargodha Board, DG Kahn Board, and Sahiwal Board. Here are the complete FSC 1st Year Physics Notes PDF of all chapters for free, visit this link.

## FSC Part 1 Physics Chapter 10 Optical Instruments Solved Exercise Notes PDF Download

#### A converging lens of focal length  5.0cm is used as a magnifying glass. If the near point of the observer is 25cm and the lens is held close to the eye, calculate i) the distance of the object from the lens ii) the angular magnification. What is the angular magnification when the final image is formed at infinity?

Data :

Focal length = f = 5cm
near point = d = 25cm
distance of the object from the lens = p =?
angular magnification = M = ?
when the image at infinity angular magnification = M =?
calculation:
as we know that lens formula given gy
1/f +1/p+1/q
since the image is virtual, so, it can be written as
1/f +1/p-1/q

Putting the value we get
1/5 = 1/p – 1/25
1/p = 1/5 +1/25 = 5+1/25 = 6/25

P = 25/6 = 4.2 cm

Angular magnification is given by
M = 1 + d/f

Putting the value we get

M = 1+ 25/5 = 1+5 = 6

M = 6
when the image is at infinity, the object must be in focus,
thus, p = f

As M  = d/p

So , M = d/f
putting the values, we get
M = 25/5
M = 5
For the remaining complete FSC 1st Year Physics Chapter 10 Solved Exercise & Numericals Notes PDF see the red-coloured download pdf button above.