Question

A 1.5m wire carries a 3 A current when a potential difference of 84 V is applied. What is the resistance of the wire?

Answer 1

The current flowing through the wire = $3 A$

The applied potential difference = $84 V$

Using Ohm's Law, that is the the voltage across the two points is directly proportional to the current flowing through the two points of the conductor. The formula is:

$I \alpha V$

$V = IR$

where V is the voltage difference, I is the current and R is the resistance of the conductor.

Substituting the values in the formula:

$84 = 3\times R$

$R = \frac{84}{3} = 28 \Omega$

So, the resistance of the wire is $28 \Omega$.

Answer 2

Resistance can be calculated using equation:

$V=I\times R$

$R=\frac{V}{I}$

Here, V denotes voltage  

I denotes current  

R denotes resistance  

Here V is given as 84 V  

I is given as 3 A  

So by putting all the values in the equation, we will get:  

$84=3\times R$

$R=\frac{84}{3}$

R=28 ohm  

So, resistance here will be 28 ohm .