The parallel combination of 2ohms and 5ohms connected are cross the external resistor of 3ohms through the supply of 4v . draw the circuit diagram and find the current through a 5ohms?

To find the current through the 5 ohm resistor, we first need to calculate the total resistance of the parallel combination of 2 ohms and 5 ohms.

1/R_total = 1/2 + 1/5
R_total = 1 / (1/2 + 1/5)
R_total = 1 / (5/10 + 2/10)
R_total = 1 / (7/10)
R_total = 10 / 7
R_total = 1.43 ohms

Now, we can calculate the total current flowing through the circuit using Ohm's Law:

I = V / R_total
I = 4V / 1.43 ohms
I = 2.79 A

Now, we can calculate the current through the 5 ohm resistor using the current divider rule:

I_5ohm = (R_total / (5 + R_total)) * I
I_5ohm = (1.43 / (5 + 1.43)) * 2.79
I_5ohm = (1.43 / 6.43) * 2.79
I_5ohm = 0.62 A

Therefore, the current through the 5 ohm resistor is 0.62 A.