Determination of ultrasonic waves velocity in liquid media
Procedure
- Insert the quartz crystal in the socket at the base and clamp it tightly with the help of a screw provided on one side of the instrument.
- Unscrew the knurled cap of the cell and lift it away. Fill the middle portion with the experimental liquid and screw the knurled cap tightly.
- Then connect the high frequency generator with the cell.
- There are two knobs on the instrument- “Adj” and “Gain”. With “Adj”, position of the needle on the ammeter is adjusted. The knob “Gain” is used to increase the sensitivity of the instrument.
- Increase the micrometer setting till the anode current in the ammeter shows a maximum.
Note the reading micrometer corresponding to the maximum or minimum (whichever is sharper) in micro-ammeter. Take about 5 readings of consecutive maximum or minimum and tabular them as shown below,
Then calculate the velocity of wave through the medium as,
Observations
Value of smallest division on main scale = m =________
Total number of division on circular scale = n=________
Least count of the micrometer =________ mm Frequency of the ultrasound used (f) = 2MHz
| S NO. | Main Scale Reading (MSR) | Circular Scale Division (CSD) | CSD x LC | Total Reading = MSR + CSR |
|---|---|---|---|---|
| 1 | ||||
| 2 | ||||
| 3 | ||||
| 4 |
Observation Table
| S NO. | Micrometer Reading corresponding to maximum/minimum (in mm) | Difference between consecutive maxima/minima (λ/2) |
|---|---|---|
| 1 | ||
| 2 | ||
| 3 | ||
| 4 | ||
| 5 |
Result
The velocity of the ultrasonic wave through the given liquid medium = _______________ ms-1