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ACTIVITY BOOK

ACTIVITY – 0 1

MAKING OF SCALE OF FIXED LEAST COUNT

Aim :  To make a paper scale of given least count e.g. 0.2 cm and 0.5 cm

Apparatus :  A thick white paper, scale, pencil, adhesive, a paper cutter etc.

Diagram :

Paper Scale of Least count 0.01cm

Paper Scale of Least count 0.02cm

Paper Scale of Least count 0.05cm

Procedure : A)     Paper scale of least count 0.2 cm.

      Take a white paper sheet and fold it in the middle along lengthwise.

      Mark the upper half along the length of line Draw a line AB of 10 cm long by a pencil.

      Put point  A as zero mark point on AB and write as 0,1,2 ,3,4,…. up to 10 at a distance of 1 cm.

      Mark the vertical lines of 4mm length on line AB at the position of each mark 0,1,2,3,4,…. up to 10.

      Draw another line CD which is parallel to AB at a distance of 10 mm from Line AB

      Draw another line XY parallel to AB at a distance of 20 mm and complete the rectangle ABYX.

      Divide each 1 cm interval into five equal divisions on AB by marking points at every interval of 2mm. Mark these points upto 10 cm mark.

      Now draw small lines of length 2 mm long perpendicular to AB on each of the point which is at a distance of 2mm.

      Darken each line and division by the sharp black pen and write 0.2,0.4,0.6,0.8 ,…. up to 10  mark.

      Cut the rectangular scale by the paper cutter along the boundary of the rectangle.

      Paper scale of least count 0.2 mm and the range 10 cm is ready.

B)     Paper scale of least count 0.5 cm.

      Repeat the first six steps as in part A of the above activity.

      Divide each 1 cm interval into  two equal divisions on AB by marking points at every interval of 5 mm and mark these points upto 10 cm mark.

      Draw small lines about 2mm long and perpendicular to AB on each of the point at a distance of 5 mm.

      Darken each line and division by the sharp black pen and write 0.5,1,1.5,2.,2.5,…. up to 10 at each 1cm mark.

      Repeat the step 10 as in part A of activity.

      Paper scale of least count 0.5 cm and the range 10 cm is ready.

Conclusion :

Students Understands the meaning of Least count .

J K L

ACTIVITY – 0 2

 LAW OF MOMENTS

Aim : To determine the mass of a given body using a meter scale by principle of moments.

Apparatus :  A meter scale suspended at C.G., hanger with slotted weights, a body of

unknown mass.

Formula:

Diagram :

Procedure :

      Balance the meter scale carefully at its Centre of Gravity (C.G. ) .

      Suspend the body of unknown mass (m₁) at a fixed distance (r₁) from C.G. as shown in figure.

      Suspend the hanger with slotted weights (m₂) at a distance (r₂) from C.G. to the other side as shown. ,

      Adjust the distance (r₂) in such a way that, the meter scale becomes horizontal.

      Repeat the above step by changing the slotted weights (m₂) and note down the corresponding distance (r₂) in each case for three times.

 Observations table :

     Fixed distance of unknown mass from C.G. r₁=……….. cm.

Sr No	Mass in hanger (m2)gm	Distance () cm	Unknown mass
01
02
03

Calculations :

Result :

The unknown mass of a body Mean mass(m₁ )          =…………. gm

J K L