Question

when a 12v battery is connected across an unknown resistor , there is a current of 2.5 mA in the circuit . find the value of resistence of the resistor

Answer 1

V=12v

I=2.5mA=2.5×10^-3 ×10 = 25× 10^-4

R= ?

R=V/I

R=12/25×10^-4

R=12×10^4/25

R=12 × 10000/25

R =4800

Therefore, R = 4800 ohms

Answer 2

Given,

Total voltage supply by a battery, to an unknown resistor = 12 V

The total current flowing in the circuit = 2.5 mA

To find,

The value of resistance of the resistor.

Solution,

We can simply solve this numerical problem by using the following process:

Mathematically, as per ohms law;

"For a voltage V across the conductor, current I flowing through the conductor and resistance R provided by the conductor to the flow of current, V = RI"

=> R = V/I

Now, according to the question;

The value of resistance of the resistor

= (voltage supply by the battery)/(total current flowing in the circuit)

= 12V / 2.5 mA

= 12V / 2.5 x 10^-3 A

= 4800 ohms

Hence, the value of resistance of the resistor is equal to 4800 ohms.