Every magnet has two poles, North and South. When it is hung freely, it always settles in the direction North and South of the Earth. The following experiment is about the properties of magnetic pendulum. In all experiments find the time period of oscillation, and find relation in the direction of vibration and the time period of pendulum. Hypothesis: The effect of changing the vibration direction of magnetic pendulum on time period of the 20 constant oscillations. Apparatus: 1. Color indicated lab magnets 2. Strings and threads 3.
Solution Tape (Transparent) 4. Measuring Scale (1 feet) 5. Set of compasses 6. Lab stand 7. Stopwatch 8. Scissors Methodology: A For Single magnetic pendulum investigation: 1. Hang a bar magnet horizontally using the thread string, tied in balance with the lab stand. The thread should be strongly tied with the magnet & stand. 2. Make sure the magnet is not rotating from its point of centre. This is done in order to allow precise timed readings, as the oscillation progresses smoothly. 3. Use two or more compasses to check the North.
Keep the compasses at a 1 meter distance from the magnets to avoid unnecessary deflection 4. Vibrate it in the direction as shown in the diagrams below. 5. Repeat steps 1-2 for varying directions Note: The side view of all direction combinations is in the horizontal plane. The top view uses vertical and horizontal terms in its own respective sense i. e. the as viewed from the bird’s eye projection. Part 1: Constant: 20 oscillations Distance of the string i. e. from the tied knot of the stand to the magnet = 6″ Variables: Time (seconds) and Direction (arrow) of magnet pendulum swings
In part 1 of the investigation, the magnet will be swung across constant amplitude with the constant no. of 20 oscillations. With each changing direction, the time period for the 20 oscillations will be noted down on paper. Then, the readings will allow us to deduce if the changing direction of magnet has an effect on the time period or not. Below are the four directions, named A, B, C and D along their time period readings. As per the results of the investigation, the change in the direction of vibration of the magnet for 20 oscillations does not affect the time period of the oscillation.
As we can see he comparison chart above, the values for directions A, B, C and D are almost same, with very minuscule micro second differences. The possible uncertainty here can be human error in timing the experiment and secondly, the quality of magnets i. e. minor change in size and weight. Moreover, the balance of the string attached was not at most in perfect form, hence the unnecessary rotating of the magnets from the point of tied knot must have affected the time period readings.
Hence, the part 1 of the investigation comes to suggests that the change in direction of the vibration of the magnet does not affect the time period of the oscillations. Part 2: Pole Combination A Methodology: B For Dual magnetic pendulum investigation: 1. Hang a bar magnet horizontally with the help of two strings. 2. Now put another magnet just below the hanging magnet, in the same direction as the hanging magnet, with similar poles facing each others. 3. Using the thread string, tied in balance with the lab stand. The thread should be strongly tied with the magnet & stand.
4. Make sure the magnet is not rotating from its point of centre. This is done in order to allow precise timed readings, as the oscillation progresses smoothly. 5. Change the distance between the two magnets, keeping the oscillations constant at 20 and then note the change in the time period. 6. Now, vibrate the magnet (for different directions) with small amplitude, first along the length then along with width. Measure the time period of vibration. Also find the rate of decrease in the amplitude of vibration. 7. Repeat 1-6 for varying direction combinations.
As per the results for part 2 of the investigation, we put hanged a magnet of the same size as used in part 1 of the investigation by a tied string, making it a dynamic object. Then, we placed a stationery magnet of the same size below it. As we vibrated the dynamic magnet along its width, we slightly altered the distance between the stationery magnet and the dynamic magnet to see if had affect on the oscillations” time period. Now, the interesting part of the investigation arises.
As you can see from the comparison chart of the same pole combination of N-N to S-S, a slight change in distance between the two magnets, that is a (1.6 minus 1. 0 = 0. 6 cm) 0. 6 cm change brings a 2. 0+ second change. The increase in the distance between the two magnets increases the time period for the 20 oscillations. The theory behind this is simple. As the two magnets move closer to each other, they face a higher amount of N to N and S to S repulsion, so they are pushed with a greater force than they would be when they would be apart (as the case is for d=1. 6 cm). This in result decreases the time period, as the 20 oscillations are completed in a lesser time period.