A transistor is operated in common-emitter configuration at Vᵥ = 2 V such that a change in the base current from 100 µA to 200 µA produces a change in the collector current from 5 […]
A transformer rated at 10 kW is used to connect a 5 kV transmission line to a 240 V circuit. The ratio of turns in the windings of a transformer
Options
(a) 5 (b) […]
If the self inductance of 500 turn coil is 125 mH, then the self inductance of similar coil of 800 turns is
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(a) 48.4 mH (b) 200 mH (c) 187.5 mH (d) 320 […]
The flux linked with a circuit is given by φ=t³+3t-7. The graph between time (x-axis) and induced emf (y-axis) will be a
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(a) straight line with negative intercept (b) straight line with […]
Two coaxial solenoids are made by winding thin insulated wire over a pipe of cross-sectional area A=10 cm² and length =20 cm. If one of the solenoids has 300 turns and the other 400 turns, […]
Which wavelengths of sun is used finally as electric energy?
Options
(a) Radio waves (b) Infra red waves (c) Visible light (d) Micro waves
Correct Answer:
Infra red waves
Explanation:
Infrared rays or heat […]
The turn ratio of a transformer is 1:2. An electrolytic dc cell of emf 2 volt is connected to its primary. The output voltage is
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(a) 2 V (b) 0 V (c) […]
A transistor-oscillator using a resonant circuit with an inductor L (of negligible resisitance) and a capacitor C in series produce oscillations of frequency f. If L is doubled and C is changed to 4C, the […]
The core of a transformer is laminated because
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(a) ratio of voltage in primary and secondary may be increased (b) energy losses due to eddy currents may be minimised (c) the weight […]
The current through an inductor changes from 3 A to 2 A is 1 m/s. If induced e.m.f. in inductor is 5V then L is
Options
(a) 5×10⁻² H (b) 5×10⁻³ H (c) 2.5×10⁻³ […]
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