Answer:
[tex]R = 24 ohm[/tex]
Explanation:
As we know that terminal voltage and EMF of cell is given as
[tex]V = EMF - ir[/tex]
[tex]ir = 12 - 11.8[/tex]
[tex]ir = 0.2 Volts[/tex]
resistance of two bulbs is given as
[tex]R = \frac{V^2}{P}[/tex]
[tex]R = \frac{12^2}{3}[/tex]
[tex]R = 48 ohm[/tex]
now these two bulbs are connected in parallel
so equivalent resistance is given as
[tex]\frac{1}{R} = \frac{1}{R_1} + \frac{1}{R_2}[/tex]
[tex]\frac{1}{R} = \frac{1}{48} + \frac{1}{48}[/tex]
so we have
[tex]R = 24 ohm[/tex]
