Correct Answer - Option 1 : To get the first deflection large
Ballistic galvanometer:
The galvanometer which is used for estimating the quantity of charge flow through it is called the ballistic galvanometer. The deflection of the coil which is directly proportional to the charge passes through it. The galvanometer measures the majority of the charge passes through it in spite of current.
Calibration of Galvanometer:
The calibration of the galvanometer is the process of determining its constant value with the help of the practical experiments. The following are the methods used for determining the constant of the ballistic galvanometer.
- Using a Capacitor
- Using a Mutual Inductance
Explanation:
- We know that an underdamped galvanometer causes a great waste of time as the coil settles to its final steady position after oscillating about it.
- An overdamped galvanometer represents very sluggish behaviour and loss of time.
- A critically damped galvanometer represents an arrangement that takes the coil to its final steady position in the minimum time that is possible without overshooting.
- The best operating conditions are attained with a galvanometer that is either critically damped or slightly underdamped which may even give a faster response.
If the damping is slightly less than the critical value the galvanometer swings a little beyond the final position on the first swing but comes to rest soon.