Question 4

(a) Three resistors 2 Ω, 4 Ω and 5 Ω are combined in parallel. What is the total resistance of the combination?

(b) If the combination is connected to a battery of emf 20 V and negligible internal resistance, determine the current through each resistor, and the total current drawn from the battery.

Answer

(a) There are three resistors of resistances,

R_{1} = 2 Ω, R_{2} = 4 Ω, and R_{3} = 5 Ω

They are connected in parallel. Hence, total resistance (R) of the combination is given by,

Therefore, total resistance of the combination is .

(b) Emf of the battery, V = 20 V

Current (I_{1}) flowing through resistor R_{1} is given by,

Current (I_{2}) flowing through resistor R_{2} is given by,

Current (I_{3}) flowing through resistor R_{3 }is given by,

Total current, I = I_{1 }+ I_{2 }+ I_{3} = 10 + 5 + 4 = 19 A

Therefore, the current through each resister is 10 A, 5 A, and 4 A respectively and the total current is 19 A.

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- NCERT Chapter

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