You are on an aluminum ladder that is standing on the ground, trying to fix an electrical connection with a metal screwdriver having a metal handle. Your body is wet because you are sweating from the exertion; therefore, it has a resistance of 1.60 kΩ .
(a) If you accidentally touch the "hot" wire connected to the 120 V line, how much current will pass through your body?
(b) How much electrical power is delivered to your body?
(a) 0.075A
(b) 9W
The voltage (V) passing across or supplied to a body is directly proportional to the current (I) flowing through the body as stated by Ohm's law. i.e
V ∝ I
=> V = I x R ----------------------(i)
Where;
R = constant of proportionality called resistance of the body
(a) As stated in the question;
The body is wet and thus will conduct electricity and has the following;
V = voltage supplied = 120V
R = resistance of the wet body = 1.60kΩ = 1.6 x 1000Ω = 1600Ω
Substitute these values into equation(i) as follows;
120 = I x 1600
Solve for I;
I = [tex]\frac{120}{1600}[/tex]
I = 0.075A
Therefore the amount of current that will pass through your body is 0.075A
(b) Electrical power(P), which is commonly measured in Watts(W), delivered to a body is the product of the current(I) and voltage (V) supplied to the body. i.e
P = I x V ---------------------(ii)
Where;
I = 0.075A [as calculated above]
V = 120V [given in the question]
Substitute these values into equation (ii) as follows;
P = 0.075 x 120
P = 9W
Therefore, the electric power delivered to your body is 9W
