Physics Test - ...

The fundamental frequency of vibration of 1 cm long string is 256 Hz. If the length of the string is reduced to 1/4cm keeping the tension unaltered, the new fundamental frequency will be :

A string of density 7.5g/cm⁻³ and area of cross-section 0.2mm² is stretched under a tension of 20N. When it is plucked at the mid point, the speed of the transverse waves on the wire is:

A sound signal is sent through a composite tube as shown in the Fig. The radius of the semicircle is r. The speed of sound in air is v. The source of sound is capable of generating frequencies in the range f₁ to f₂ (f₂ > f₁). If nn is an integer, frequency for maximum intensity is given by :

When a stationary wave is formed, then its frequency is :

A uniform string is vibrating with a fundamental frequency 'f'. The new frequency, if radius and length both are doubted would be:

A source of unknown frequency gives 4 beats/s, when sounded with a source of known frequency 250 Hz. The second harmonic of the source of unknown frequency gives five beats per seconds, when sounded with a source of frequency 513 Hz. The unknown frequency is :

A car is moving at a velocity of 17 ms⁻¹ towards an approaching bus that blows a horn at a frequency of 640 Hz on a straight track. The frequency of this horn appears to be 680 Hz to the car driver. If the velocity of sound in air is 340 ms⁻¹, then the velocity of the approaching bus is:

The length of an open organ pipe is twice the length of another closed organ pipe. The fundamental frequency of the open pipe is 100 Hz. The frequency of the third harmonic of the closed pipe is:

A block of wood of side 40 cm floats in water in such a way that it lower face is 5 cm below the free surface of water. What is the weight of the blocks?