Question

two resistance 5 and 5 ohm are connected in series to a 20V battery then find current in this circuit.

Answer 1

Explanations & Calculations

• Equivalent resistance of resistors in series is given by $\small R_e= R_1+R_2+R_3+........$
• According to that, equivalent of these 2 resistors can be calculated to be $\small (5\Omega+5\Omega) = 10\Omega$ .
• Then the 20V voltage can be considered applied across this equivalence.
• Applying the Ohms law (V=iR), the current can be calculated.

$\qquad\qquad \begin{aligned} \small i &= \small \frac{20V}{10\Omega} = \bold{2A} \end{aligned}$

Another method

• Using kirchhoff's voltage law to the closed circuit along the current flowing direction (if the flowing current is $\small i_1$ )

$\qquad\qquad \begin{aligned} \small 20V &= \small 5i_1+5 i_1\\ \small i_1&= \small \bold{2A} \end{aligned}$