Question

If there is two batteries connected in series, each battery is 6V. What is the EMF of the battery?​

Answer 1

The EMF of each battery is 6 volts and the EMF of two batteries connected in series is 12 volts.

Step-by-step explanation:

According to the Kirchhoff's Voltage Law, net voltage of a closed circuit must be zero. That is:

`\Sigma \limits_(i=1)^(n) V_(i) = 0` (1)

Where
`V_(i)` is the voltage of the i-th component of the closed circuit, measured in volts. Please notice that voltage for a power generating element (i.e. EMF) is less than zero and for a power consuming element is greater than zero (i.e. Batteries being charged by the EMF). In addition, if n-elements are connected in series, then the equivalent voltage is:

`V_(eq) = \Sigma\limits_(i = 1)^(n) V_(i)` (2)

Let consider that closed system is formed by two batteries connected in series and an EMF, by (1) and (2) we have that:

`V_(EMF) - V_(eq,batt) = 0`

`V_(EMF) = V_(1)+V_(2)` (3)

If we know that
`V_(1) = V_(2) = 6\,V`, then the EMF of the battery is:

`V_(EMF) = 12\,V`

The EMF of each battery is 6 volts and the EMF of two batteries connected in series is 12 volts.