Igcse Model Questions Vol1 2022 Physics Question 28

Practice objective / multiple choice question 28 from the 2022 Igcse Model Questions Vol1 Physics examination.

Igcse Model Questions Vol1 2022 Physics Objective / Multiple Choice Hard Difficulty
Question 28 IGCSE_MODEL_QUESTIONS_VOL1 • 2022 • PHYSICS • objective

A 12 V battery has an internal resistance \(r\) and supplies a lamp of resistance \(R\). When the lamp draws a current of \(2.0\ \text{A}\) the terminal voltage across the lamp is measured to be \(9.0\ \text{V}\). (a) Determine the internal resistance \(r\) of the battery (in ohms). (b) Calculate the efficiency of the battery, defined as the ratio of power delivered to the external circuit to the total power generated, expressed as a percentage. (c) If a second identical lamp is connected in parallel with the first, what is the new terminal voltage across the lamps? Give your answer to two decimal places.

Answer Options

A. r = 1.8 Ω; efficiency = 70%; new terminal voltage = 7.00 V
B. r = 1.0 Ω; efficiency = 80%; new terminal voltage = 7.50 V
Correct Answer C. r = 1.5 Ω; efficiency = 75%; new terminal voltage = 7.20 V
D. r = 2.0 Ω; efficiency = 60%; new terminal voltage = 6.80 V
Correct Answer
C
Correct Option:
r = 1.5 Ω; efficiency = 75%; new terminal voltage = 7.20 V

About This Question

This is Igcse Model Questions Vol1 2022 Physics Question 28. It is one of the objective questions from the 2022 Igcse Model Questions Vol1 Physics examination.

Difficulty level: Hard .

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