When different resistors are connected in series combination the current passing through them remains the same.
Veq = V1 + V2 + V3 +… +Vn)
Since, V= IR
Putting the value in the above equation.
Veq = I(R1 + R2 + R3…+ Rn)
I Req = I (R1 + R2 + R3…+ Rn)
Req= (R1 + R2 + R3…+Rn)
Thus, we can say that the current remain constanct in series connection.