Question

the current in a simple series circuit is 5 ampere when an additional resistance of 2 ohm is inserted the current drops to 4 ampere the orignal resistance of circuit is once tell please though its a simple qsn

Answer 1

I = 5 A    Resistance = R
I' = 4 A    R' = R+2  Ω     = total resistance

We assume R is the total effective resistance in the circuit in series with the battery.  Also, that 2 Ω resistance is added in series with the= given resistance and battery.

   Voltage of the battery = E = I R = I' R'
     5 * R = 4 ( R +2)
     =>  R = 8 Ω
 
   battery potential is =  40 V

Answer 2

First pls type the complete question , In complete question , it has been said that V is same , so ,

Ohk then let R is the original resistance then ,

V/R = 5 & V/R+2 = 2

Dividing ,

R+2/ R = 5/4

R = 8 ohm