Neco Model Questions Vol1 2020 Physics Question 15

Practice objective / multiple choice question 15 from the 2020 Neco Model Questions Vol1 Physics examination.

Neco Model Questions Vol1 2020 Physics Objective / Multiple Choice Hard Difficulty
Question 15 NECO_MODEL_QUESTIONS_VOL1 • 2020 • PHYSICS • objective

A battery of emf \(E = 12\,\text{V}\) has an internal resistance \(r\). It is connected to an external circuit consisting of two resistors \(R_{1}=6\,\Omega\) and \(R_{2}=12\,\Omega\) connected in parallel. The terminal voltage across the external circuit is measured to be \(9\,\text{V}\). Determine (a) the internal resistance \(r\) of the battery (in ohms), (b) the total current supplied by the battery (in amperes), (c) the power dissipated in the internal resistance (in watts), and (d) the efficiency of the battery (percentage of the total power delivered to the external circuit).

Answer Options

Correct Answer A. r = 4/3 Ω; total current = 2.25 A; internal power = 6.75 W; efficiency = 75 %
B. r = 2 Ω; total current = 2.0 A; internal power = 8.0 W; efficiency = 70 %
C. r = 1 Ω; total current = 2.5 A; internal power = 6.25 W; efficiency = 80 %
D. r = 3/2 Ω; total current = 2.0 A; internal power = 6.0 W; efficiency = 66 %
Correct Answer
A
Correct Option:
r = 4/3 Ω; total current = 2.25 A; internal power = 6.75 W; efficiency = 75 %

About This Question

This is Neco Model Questions Vol1 2020 Physics Question 15. It is one of the objective questions from the 2020 Neco Model Questions Vol1 Physics examination.

Difficulty level: Hard .

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