Objective:
1. To measure the distances between maxima and minima points.
Theory:
Standing waves are produced whenever two waves of identical frequency interfere with one another while traveling opposite directions along the same medium. Standing wave patterns are characterized by certain fixed points along the medium which undergo no displacement. These points of no displacement are called nodes (nodes can be remembered as points of no displacement). Midway between every consecutive nodal point are points which undergo maximum displacement. These points are called antinodes. The nodes are points of no displacement caused by the destructive interference of the two waves. The antinodes result from the constructive interference of the two waves and thus undergo maximum displacement from the rest position.
Equipments & Accessories:
1. Microwave Communication Base
2. Microwave Transmitter
3. Microwave Receiver
4. 1 Probe
5. Tape Measure
Figure:
Figure: Standing wave measurement
Formulation:
1. f=c/λ
Calculation & Result:
| Nodes (cm) | Antinodes (cm) |
| 0.75 | 0.0 |
| 2.5 | 1.5 |
| 3.6 | 3.0 |
| Nodes (cm) | Antinodes (cm) |
| 5.0 | 4.3 |
| 6.6 | 5.7 |
Frequency Calculation for the nodes and Antinodes:
(2.5-0.75) cm = 1.75 cm
λ/2 = 1.75
λ = 3.5 cm
Now, f= c/λ
f= (3* 10^10) cm/3.5 cm
f= 8.57 GHz
Again,
(3.6-2.5) cm= 1.1 cm
λ/2 = 1.1
λ= 2.2 cm
Now, f= c/λ
f= (3* 10^10) cm/2.2 cm
f= 13.6 GHz
Following the same process we get 10.71 GHz & 9.37 GHz
The average frequency is,
(8.57+ 13.6+ 10.71+ 9.37)GHz/4
= 10.56 GHz
Following the same process as the node we get the average frequency of antinode is,
(10 + 10 + 11.53 + 10.71) GHz/4
= 10.56 GHz
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