Page 72 - Physics - XI

Activities
Activities

Activity - 1

Aim

To make a paper scale of given least count, e.g. 0.2 cm, 0.5 cm.

Apparatus and Materials Required
A thick white paper sheet, pencil, scale with sharp edge marked in cm and mm, fevicol, a pair of scissors, a
paper cutter, and thick ivory sheet used by engineering students
Q
P B
A 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
R S

X
Fig. 1.1: Scale of least count 0.2 cm Y

Q
P
A 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 B
R S

X
Fig. 1.2: Scale of least count 0.5 cm Y
Principle/Theory

Least count: The minimum measurement that can be measured by an instrument accurately is called the
least count of the instrument.
Range of an instrument: The diff erence between maximum and minimum readings taken by an instrument
is called the range of the instrument.

Procedure

A. Procedure of making Paper scale of least count 0.2 cm
1. Fold a white paper sheet in the middle along lengthwise.
2. Mark in the upper half along the length a line PQ 15 cm long by a sharp pencil [Fig. 1.1].

3. Take the point P as zero mark point on PQ and start marking the small dots after every 1 cm distance
and write 0, 1, 2, … up to 15 at successive dots.

4. Mark the vertical lines to line PQ at the position of each mark 0, 1, 2, _____ _____ up to 15.
5. Draw another sharp line RS which is parallel to PQ at a distance of 8 mm.

6. Draw another line XY parallel to PQ at a distance of about 25 mm and complete the rectangle PQYX.
Darken the rectangle using sharp black ink pen.

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