Draw a labelled diagram of a magnetic relay and explain it's working

Relay is a controlling device just like a switch. handling high current with smaller current is the function of the relay.

Explanation:

There is a coil with the iron core is used as an electromagnet to operate the contact switch. When the control switch is closed the magnet operates the contact closed by attracting the metal terminal of the contacts switch. then current will passed throw the contact switch to load. When the control switch is open, the magnetic force will release and open the contact switch.

In a lot of applications, these replays are used to operate to control high current. it can control both AC and DC, but the magnetic coil works only dc.

the word that best describes martin luther king jr.'s tone in the video is dignified

martin luther king, jr. was a social activist and baptist minister who played a key role in the american civil rights movement from the mid-1950s until his assassination in 1968. the video shows his manner and attitude having or showing a composed or serious manner that is worthy of respect so dignified is the correct answer

electric field is a function of 1/r^2

yes, the force per unit charge for a point charge is inverse square law.