Determine the Acceleration due to gravity ‘g’ using Kater’s Pendulum Experiment

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 Kater’s Pendulum

Aim :

To determine the acceleration due to gravity ‘g’ using Kater’s Pendulum.

Apparatus :

Kater’s Pendulum, telescope, stop watch, knife-edge, meter-scale, etc.
Kater's Pendulum - To determine value of Gravity 'g'

 

Formula :

Where ‘l1’ and ‘l2’ distance between the Knife edge K1 and K2 from center of gravity respectively and ‘g’ is gravitational acceleration.

Diagram :


Kater's Pendulum

 

Procedure :

Kater pendulum software here

Credit : All Lab Experiments

  1. Fixed the heavy (metal) mass of the Kater’s Pendulum at one end and wooden mass at the other end of the bar so that it is symmetrical about the mid point of the bar.
  2. Name the two knife edges K1 and K2, Fix the knife edges K1 and K2 Fix the smaller weights between the two knife edges such that it is always symmetrical about mid point of the bar.
  3. Suspend kater’s pendulum alternately from its knife edges (K1 and K2) and measure the respective time intervals t1 and t2 for 10 oscillation. Shifting the position of any of the knife edges and/or movable masses make the two time intervals as nearly equal as possible. Tabulate all the trial readings.
  4. When the time period T1 and T2 are nearest (0.04 Sec) possible, then find t1 and t2 for 100 oscillations about k1 and k2 atleast 3 times respectively. Hence calculate period of oscillations T1 = t1/100 and T2 = t2/100.
  5. Take the pendulum down and measure the distance ‘L1’ between the two knife edges.
  6. Balance the pendulum on knife edge & determine its centre of gravity and measure the distance l1 and l2 of knife edges k1 and k2 respectively from center of gravity.
  7. Now change L1 = l1+l2 slightly (by about 1cm) to L2 and find the new time periods T1 and T2.
  8. Hencee calculate ‘g’ by using the formulae.

Observations :

 

Viva Question and Answers [FAQ] :

1. Give the Example of compound pendulum?

Ans :
  • Bar pendulum
  • Kater’s pendulum
  • Pendulum in a clock

2. What are the components of a pendulum?

Ans :
  • Center of suspension
  • Center of gravity
  • Center of oscillation

3. Which one provides the most accurate value of ‘g’?

Ans : Kater’s pendulum

4. What is the difference between simple and compound pendulum?

Ans : In simple pendulum, center of gravity and center of oscillation are approximately the same.

In compound pendulum, center of gravity and center of oscillation are distant apart.

5. What is the length of a pendulum?

Ans : The distance between the ‘center of suspension’ and ‘center of oscillation’ is the length or pendulum.

6. What is a Seconds pendulum?

Ans : A pendulum whose period of oscillation is exactly 2 seconds.

7. What are the applications of kater’s pendulum?

Ans :
  •  Accurate measurement of time.
  •  Accurate value of ‘g’
  •  Find the minerals and for other geophysical surveys.

8. What is the difference between ‘g’ and ‘G’?

Ans : ‘g’ is acceleration due to gravity. ‘G’ is a universal constant.

9. Katers pendulum is which type of pendulum?

Ans : Reversible compound pendulum.

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