Question

The fact that lightning and spark are essentially the same phenomena was discovered in
A. $1882$
B. $1752$
C. $1770$
D. $1802$

Answer 1

Hint: An electric spark occurs when there is a sudden flow of electric current. Lightning is nothing but a huge electric spark or the discharge of charges in the sky.
It was Benjamin Franklin who discovered this through his famous kite experiment.

Complete step by step answer:
The fact that lightning and spark are essentially the same phenomena was discovered by Benjamin Franklin through his famous kite experiment. He conducted this experiment in $1752$.
In his experiment he let a kite fly high into the sky on a stormy day during the time of lightning. He tied a metal key to the end of the kite string. At the time of lightning he suddenly felt an electric shock. Thus, he realized that lightning is similar to an electric discharge. To confirm he repeated the experiment again and felt shock during the second time also. So, he came to the conclusion that lightning is an electric discharge. It was the electric charge of the lightning that was conducted by the metal which is a good conductor of electricity. Thus, lightning is nothing but a huge electric spark or the discharge of charges in the sky. An electric spark occurs when there is a sudden flow of electric current. When high current is discharged through the air the air molecules get heated up. This causes the glow that we see in lightning.
$\therefore$ The correct answer is option B

Note: Before Benjamin franklin's experiment the connection between lightning and electricity was known but was not fully understood. This experiment brought out the fact that both are essentially the same. This experiment also led to the invention of the lightning rod which is used to protect buildings.