To Study the Effect of Load on Depression of a Suitably Clamped Metre Scale Loaded at (i) its end (ii) in the Middle

Aim 
To study the effect of load on depression of a suitably clamped metre scale loaded at (i) its end (ii) in the middle.

Apparatus
A uniform straight wooden metre rod (scale). Two G clamp, pointer pin, thread, slotted weights of 50 g each, wax, vertical scale, clamp stand.

Theory 
to-study-the-effect-of-load-on-depression-of-a-suitably-clamped-metre-scale-1

Diagram 
to-study-the-effect-of-load-on-depression-of-a-suitably-clamped-metre-scale-2

Procedure 
(i) When metre scale is loaded at its end :
1. Clamp the metre scale firmly with G clamp at its one edge on the corner of table such that metre scale remains straight in horizontal plane.
2. The pointer pin or needle should be attached at free end of metre scale with wax.
3. Fix the scale on a stand vertically to take the reading.
4. Note the initial reading on vertical scale corresponding to the tip of the pointer when no weights is suspended.
5. Suspend the weights in steps at free end of metre scale with the help of a strong thread and note the corresponding readings on the vertical scale.
6. After taking 5-6 reading, start unloading the weights one by one and again note the reading on scale.
(ii) When metre scale is loaded in the middle :
7. Locate the C.G. of metre scale by suspending it with a thread.
8. Now, place the metre scale symmetrically on two knife edges them about 85 cm apart and check that metre scale is perfectly horizontal.
9. A pointer is attached at the mid point of the scale with the help of wax or adhesive tape to take the reading.
10. Repeat the steps 3 to 6 and record the observation in the table.

Observations 
1. Initial reading of pointer on vertical scale without loading at free end = x0 =……..cm
Table for load and depression when metre rod is loaded at its one end.
to-study-the-effect-of-load-on-depression-of-a-suitably-clamped-metre-scale-3
2. Initial reading of pointer on vertical scale without loading in the middle =x0 =…………cm
Table for load and depression when metre rod is loaded at its one end.
to-study-the-effect-of-load-on-depression-of-a-suitably-clamped-metre-scale-4

Graph 
Plot a graph between load and depression by taking load on X-axis and depression on Y- axis for both of cases. In both the cases, graphs come to be a straight line as shown below.
to-study-the-effect-of-load-on-depression-of-a-suitably-clamped-metre-scale-5

Result 
The graph between load and depression are straight lines, which gives that depression is directly proportion to the load.
to-study-the-effect-of-load-on-depression-of-a-suitably-clamped-metre-scale-6

Precautions

  1. The metre scale should be straight and uniform and clamped firmly.
  2. The tip of pointer should not touch the vertical scale.
  3. The scale should not be loaded beyond the elastic limit.
  4. Reading on metre scale should be taken carefully.

Sources of error 

  1. The metre scale may be non-uniform.
  2. The tip of pointer may not be very sharp.

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