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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%
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Topics: Alternating Current
(96)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- The magnifying power of the astronomical telescope for normal adjustment is 50.
- An a.c. supply gives 30 volt r.m.s which passes through a 10Ω resistance.
- The flux linked with a coil at any intant t is given by ?=10t² – 50t + 250
- Einstein’s photoelectric equation is
- In a thermodynamic system, working substance is ideal gas. Its internal energy
Topics: Alternating Current (96)
Subject: Physics (2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
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