For normal ears, sensitivity is maximum at the frequency :

1. 5 kHz
2. 10 kHz
3. 1 kHz
4. 500 Hz

By reducing the amplitude of the sound wave, its :

1. pitch decreases
2. loudness decreases
3. loudness increases
4. pitch increases

Two sounds of the same loudness and same pitch produced by two different instruments differ in their

1. amplitudes
2. frequencies
3. wave forms
4. all the above

Instruments A and B are producing sounds of the same amplitude, same waveform but frequencies F and 2F respectively. Which of the following statements is correct ?

1. both A and B differ in quality
2. B is grave but A is shrill
3. A is grave but B is shrill
4. B is louder than A