Sound and Light

The range of frequency for a healthy human ear is ...

• 20 Hz - 2000 Hz

• 2 Hz - 200 Hz

• 20 Hz - 20000 Hz

• 2 Hz - 20000 Hz

What do you mean by ultrasound?

• above the animal hearing range

• above the human hearing range

• below the animal hearing range

• below the human hearing range

The speed of sound in air is 340 m/s. If the frequency of the sound produced by a source is 20Hz, calculate the wavelength of the sound.

• 17m

• 1.7m

• 0.17m

• 0.017m

A reflected sound wave is an ....

Sound wave is a ______ wave.

• transverse

• longitudinal

• tidal

• normal

A flute is a _____ instrument.

• Stringed

• Percussion

• Wind

• None of the choices

The law of reflection states that the angle of incidence is equal to the ...

• critical angle

• angle of diffraction

• angle of refraction

• angle of reflection

In the figure, what letter represents the image?

Where is the object?

• P

• Q

• R

• S

What letter represents the principal focus?