-- In combination with 610 Hz, the beat frequency is 4 Hz.
So the unknown frequency is either (610+4) = 614 Hz
or else (610-4) = 606 Hz.
In combination with 605 Hz, the beat frequency will be
either (614-605) = 9 Hz or else (606-605) = 1 Hz.
-- In actuality, when combined with the 605 Hz, the beat
frequency is too high to count accurately. That must be
the 9 Hz rather than the 1 Hz.
So the unknown is (605+9) = 614 Hz.
When a current flows through coil, magnetic field is produced around the coil which induces emf also known as back emf. When current in the coil is increased, more magnetic field is produced which in turn increases the induced emf.
Air, water , atomic acid , and pocket rocket
What happens when the light hits the glass depends on what it was in before it hit the glass.
WHILE it's in the glass, the speed of light doesn't change.
