NCERT Exemplar Problems

A girl is sitting in the middle of a park of dimension $12 \mathrm{m}\times 12 \mathrm{m}$. On the left side of it, there is a building adjoining the park and on the right side to the park, there is a road adjoining by park. A sound is produced on the road by a cracker. It is possible for the girl to hear the echo of this sound? Explain your answer.

If any explosion takes place at the bottom of a lake, what type of shock waves in water will take place?

Represent graphically by two separate diagrams in each case: Two sound waves having the same amplitude but different frequencies.

Represent graphically by two separate diagrams in each case: Two sound waves having the same frequency but different amplitudes.

Represent graphically by two separate diagrams in each case: Two sound waves having different amplitudes and also different wavelengths.

Establish relationship between speed of sound, its wavelength and frequency. If velocity of sound in air is $340 {\mathrm{ms}}^{-1}$, calculate wavelength when frequency is $256 \mathrm{Hz}$.

Establish relationship between speed of sound, its wavelength and frequency. If velocity of sound in air is $340 {\mathrm{ms}}^{-1}$, calculate frequency when wavelength is $0.85 \mathrm{m}$.

Draw a curve showing density or pressure variations with respect to distance for a disturbance produced by sound. Mark the position of compression and rarefaction on this curve. Also define wavelength and time period using this curve.