Answer:
(A)
(B)
Explanation:
We have given inductance
Resistance
Time constant of RL circuit is equal to
Battery voltage e = 16 volt
(a) It is given current becomes 79.9% of its final value
Current in RL circuit is given by
According to question
(b) Current at
As per the the question the sound source is the mosquito.
the mosquito produces the sound with the help of its wings
as per the question the wings vibrate at the rate of 500 vibrations per second.
we have been asked to calculate the time period of vibration.
we know that that time period is the reciprocal of frequency of vibration
hence time period [T]=
=
=
=0.002 second
hence the time period of the vibration of the wings of the mosquito is 0.002 second.