Biology, Chemistry and Physics
To solve this problem it is necessary to apply the concepts related to mutual inductance in a solenoid.
This definition is described in the following equation as,

Where,
permeability of free space
Number of turns in solenoid 1
Number of turns in solenoid 2
Cross sectional area of solenoid
l = Length of the solenoid
Part A )
Our values are given as,





Substituting,



PART B) Considering that many of the variables remain unchanged in the second solenoid, such as the increase in the radius or magnetic field, we can conclude that mutual inducantia will appear the same.
Answer:
Explanation:
Expression for time period of a pendulum is as follows
T = 
l is length of pendulum from centre of bob and g is acceleration due to gravity
Given
Time period T = 1.583
g = 9.846
Substituting the values
1.583 = 
l = 
l = .6244 m
= 62.44 cm
Length of rod = length of pendulum - radius of bob
= 62.44 - 13.62
= 48.82 cm
= .488 m