The calculation formula of circuit in junior high school

The calculation formula of circuit in junior high school

In series circuit: I = I1 = I2
U=U1=U2
R=R1+R2
I1:I2=R1:R2；
In parallel circuit: I = I1 + I2
U=U1=U2
R=RI*R2/（R1+R2）
I1：I2=R2：R1

On the formula and relationship of circuit in junior high school
What is the ratio of current to resistance in series / parallel connection
It's all right

When the resistors are in series
The current is equal and the voltage is proportional to the resistance
I1=I2 U1:U2=R1:R2
In parallel
The voltage is equal and the current is inversely proportional to the resistance
U1=U2 I1:I2=R2:R1
Ampere's Law: u = IR
Power formula: P = UI = I * I * r = u * U / R

Questions about physical current formula
One is I = q / T
One is I = nqsv
I have doubts about the Q of these two formulas
Sometimes it's a little confusing
Especially NQ

I=Q/T
An electric current is equal to the amount of charge passing through a unit of time
Q -- is the total amount of charge passing through the cross section of conductor in time t
T -- duration
I=nqSv
N -- the number of electrons per unit volume
Q -- the basic electric quantity of the electron
S -- cross sectional area of conductor
V -- the speed of directional movement of electrons

What is the formula of heat in physics?

Q=cm(t1-t2)