Fiber optic cable, twisted pair cable and coaxial cable are three major types of network cables used in communication systems
As we know that magnetic field strength due to solenoid is given by

here we know that
= permeability of air medium
N = number of turns
L = length of solenoid
i = electric current
Now as we enter the iron rod into the solenoid the medium will get change that will increase the permeability
so with the iron rod we will have

so correct answer will be
<u>It increases the magnetic field’s strength. </u>
Answer:

Explanation:
Given data
Length L=2.9 cm=0.029m
Speed of sound v=335 m/s
to find
Fundamental frequency f
Solution
As we know that frequency is given as:
f=v/λ

<span>The </span>pineal gland<span> produces melatonin, a serotonin derived hormone which modulates sleep patterns in both circadian and seasonal cycles.</span>