Physics Test #8 – Sound Reflection, Echo & SONAR

1. The angle of incidence is equal to:
a) 0° b) Angle of reflection c) Angle of deviation d) 90°

2. A true echo is heard after a minimum time gap of:
a) 0.01 s b) 0.05 s c) 0.1 s d) 0.2 s

3. The main difference between echo and reverberation is:
a) Direction only b) Time delay between sound and reflection c) Intensity d) No real difference

4. SONAR is mainly used for:
a) Detecting aircraft b) Navigating underwater objects c) Measuring temperature d) Sound in air

5. Which type of surface best reflects sound waves?
a) Rough and soft b) Smooth and hard c) Porous and soft d) Angular plastic

6. Soundproof rooms use:
a) Soft foam walls b) Steel coatings c) Reflectors d) Concrete panels

7. If sound takes 1 second to return in echo, and velocity is 340 m/s, the reflecting surface is at:
a) 340 m b) 170 m c) 85 m d) 68 m

8. The correct formula relating speed, distance and echo time is:
a) v = d / t b) v = 2d / t c) v = t / d d) v = d × t

9. Echo can only be heard if the minimum distance between source and obstacle is:
a) 5 m b) 10 m c) 17.2 m d) 50 m

10. Ultrasonic sound waves used in SONAR have frequency:
a) < 20 Hz b) 20–20,000 Hz c) > 20,000 Hz d) Exactly 10,000 Hz

📊 Your Score

🎉 Type FINAL to export your entire Physics & Chemistry Test Series!
🧪 Ready for Biology? Type BIO1 to begin NEET Bio Foundation.