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A transformer is used to light a 100 W and 110 V lamp from a 220 V mains. If the main current is 0.5 amp, the efficiency of the transformer is approximately
Options
(a) 50%
(b) 90%
(c) 10%
(d) 30%
Correct Answer:
90%
Explanation:
? = P output / P input x 100
= 100 / 220 x 0.5 = 90.9%
Related Questions: - A parallel plate air capacitor of capacitance C is connected to a cell of emf
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Topics: Alternating Current
(96)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- A parallel plate air capacitor of capacitance C is connected to a cell of emf
- If the length of a stretched string is shortened by 4% and the tension is increased
- Two nuclei have their mass numbers into the ratio of 1:3
- The wavelength of kα, X-rays produced by an X-ray tube 0.76Å. The atomic number
- A beaker of radius 1.5 cm is filled with a liquid of surface tension 0.075 N/m
Topics: Alternating Current (96)
Subject: Physics (2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
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