To form a node there should be superposition of this wave with the reflected wave. The reflected wave should travel in opposite direction with a phase change of $$\pi $$. The equation of the reflected wave will be
A tuning fork arrangement (pair) produces $$4$$ beats/sec with one fork of frequency $$288$$ $$cps.$$ A little wax is placed on the unknown fork and it then produces $$2$$ beats/sec. The frequency of the unknown fork is
A tuning fork produces $$4$$ beats/sec with another tuning fork of frequency $$288$$ cps. From this information we can conclude that the frequency of unknown fork is $$288+4$$ $$cps$$ or $$288-4$$ $$cps$$ i.e. $$292$$ $$cps$$ or $$284$$ $$cps.$$
Here when a little wax is placed on the unknown fork, it decreases the frequency of unknown fork. Here also beats per second decreases to 2 from 4. So the difference between frequency decreases.
This is possible only when before placing the wax, the frequency of unknown fork is greater than the frequency of the given tuning fork.
So the frequency of the unknown tuninh fork is = 292 Hz
Questions Asked from Waves
On those following papers in MCQ (Single Correct Answer)
Number in Brackets after Paper Indicates No. of Questions