Question

when a 12V battery is connected across an unknown resistors there is a current of 3mA in the circuit then find the resistance of the resistor

Answer 1

Given, current (I) = 3 milliampere = 3/1000 Ampere

Voltage or potential difference (P.D) = 12V

We know, V = IR
Therefore, R = V/I
or. R = 12 / 3/1000
= 0.036 ohm



Hope this helps

Answer 2

Question:

When a 12V battery is connected across an unknown resistors there is a current of 3mA in the circuit then find the resistance of the resistor.

Solution:

$\rm\underline\blue{Given:-}$

•Potential Difference (V) = 12V

•Current (ꀤ) = 3mA

=> We have to convert milliamperes (mA) into ampere (A).

→ Current (ꀤ) = 3mA

→ Current (ꀤ) = $\sf\dfrac{3}{1000}$A

→ Current (ꀤ) = 0.003A

$\rm\underline\orange{To\:find:-}$

•Resistance (R) = ?

$\rm\underline\red{From\:Ohm's\:Law:-}$

R = $\sf\dfrac{V}{I}$

R = $\sf\dfrac{12}{0.003}$

R = $\cancel\dfrac{12}{0.003}$

R = 4000Ω

➵Therefore, Resistance (R) = 4000Ω.

$\rm\underline\pink{More\:to\:know:-}$

☆The SI unit of electric current is Ampere.

☆The SI unit of resistivity is ohm-m.