A worker is in contact with an electric drill press case by one hand. The Hot 220-VAC wire has short circuited to the metal case. He is standing with one foot in a puddle of water and the other foot on an old, deteriorated rubber mat. Calculate the total current flowing through the body and discuss the possible injury to the worker.

Explanation:

The electric current will only flow the body of worker when the path of current is complete.

The metal case of devices is usually grounded which means if the worker get in touch with the ground then the path of the current will be completed and the worker will electrocuted.

Worker is standing with one foot in a puddle of water and the other foot on an old, deteriorated rubber mat.

There are two possibilities here:

1. We know that rubber is an insulator and doesn't conduct current which means path of the current wont be completed and the worker wont be electrocuted.

2. Since the rubber mat is deteriorated, its resistance would be really low against the current which means the path of the current will be completed through rubber mat to his body to ground and he will be electrocuted.

How much current will flow?

The flow of current depends upon the resistance offered by the human body. The body resistance of humans can be as high as 100,000 Ω. Whereas the least resistance can be as low as 1000 Ω if the body is wet.

At 100,000 Ω

I = V/R = 240/100k = 2.4 mA

At 1000 Ω

I = V/R = 240/1k = 240 mA

Lets discuss the aftermaths of the electric shock:

The electric shock depends on the magnitude of current and also the time of how long the contact is.

A high current for a very short period of time might cause less damage than a low current for long period of time. The minimum current of 2.4 mA is enough to cause pain and can turn out to be dangerous if the contact period is extended.

On the other hand, the maximum current of 240 mA is enough to stop your heart within few seconds and lead to death in a short period of time.

answer:

okay

explanation: