Question

Calculate the current in a 75 Ω resistor when a potential difference of 115 V is placed across it. What will the current be if the resistor is replaced with a 47 Ω resistor?

Answer 1

Answer:

1.53A; 2.45A

Explanation:

According to ohm's law which states that the current passing through a metallic conductor at constant temperature is directly proportional to the potential difference across its ends. Mathematically,

V = IR where;

V is the potential difference

I is the current

R is the Resistance.

If a a potential difference of 115 V is placed across 75ohms resistor, the current in the resistor can be calculated as;

I = V/R where;

V = 115V

R = 75ohms

I = 115/75

I = 1.53A

If the resistor is replaced with a 47ohms resistor, the current I'm the resistor will be calculated as;

I = V/R

I = 115/47

I = 2.45A

According to the answers, the current decreases with increasing resistance because resistance tends to oppose the flow of current.

Answer 2

Answer:

$i = 1.533\,A$, $i = 2.447\,A$

Explanation:

The current is determined by the Ohm's Law:

$\Delta V = i \cdot R$

$i = \frac{\Delta V}{R}$

The current in a $75\,\Omega$ Resistor is:

$i=\frac{115\,V}{75\,\Omega}$

$i = 1.533\,A$

If current resistor is replaced by $47\,\Omega$ model, then the current is:

$i = \frac{115\,V}{47\,\Omega}$

$i = 2.447\,A$