Marks are awarded here:
1. Signal generator connected to loudspeaker
2. Microphone connected to CRO
3. Output measured for various frequencies
4. Output determined by size of peak on CRO
5. CRO used to measure frequency
6. Experiment performed away from external noise
7. Use of CRO to measure frequency (one more marks possible if period T and time base is mentioned )
8 Distance from loudspeaker to microphone constant
9. Monitor output from signal generator and keep output (amplitude)constant.
The signal generator output(amplitude) also needs the be monitored using the CRO.
The marks above are awarded by examiner and hence this is what i would present in report .
Aim : To investigate how the output of a microphone varies with the freq of the sound waves keeping the amplitude of the source constant.
Statement copied from question adding the constant of variable of the greatest importance. Other constant of variables like distance can be mentioned later.
Diagram: Signal generator (box) connected to loudspeaker. Other side , microphone connected to CRO(box) . Lable correctly.No 3D digrams and no values needed.
Procedure:
1. Set up the expt as above.
2. Adjust the signal generator and note the peak voltage of the signal generator. Keep this value constant.
3. Measure the microphone output using the CRO. Record the amplitude Vo by taking note of the y sensitivity of the CRO. Record the period T by taking note of the time base scale of the CRO.
4 Calculate the freq using the formula f= 1/T.
5 Repeat step 2 to 4 by varying the freq of the signal generator to obtain 6 sets of f and Vo.
6. Plot a graph of lg Vo against lg f . Assuming that Vo and f is related by the
equation Vo=kfn.If the graph is linear , the equation is valid and the gradient = n and the intercept = lg k .
Reliability:
Ensure that the distance between loudspeaker and microphone is kept constant.
Ensure that there are no other sources of sound around the microphone.
