Question

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

Answer 1

Answer:

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

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.