Question

3 bulbs of resistance 20 ohms are connected in series circuitwith a 12 V battery. Find current.

Answer 1

Answer :

current = 0.2 A

Explanation :

$\underline{\underline{\bf Series \ circuits:}}$

• Resistors are arranged in a chain.
• Current is same through each resistor
• Equivalent resistance, R = R₁ + R₂ + R₃ + ....

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Given,

3 bulbs of resistance 20 Ω each are connected in series circuit with a 12 V battery.              

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R₁ = R₂ = R₃ = 20 Ω

V = 12 V

I = ?

Equivalent resistance, R = R₁ + R₂ + R₃

                                     R = 20 + 20 + 20

                                     R = 60 Ω

From Ohm's law,

 which states that the voltage across a conductor is directly proportional to the current flowing through it.

       $\boxed{\bf V=IR}$

Substituting the values,

        12 = I × 60

         I = 12/60

         I = 1/5

         I = 0.2 A

∴ Current = 0.2 A