Eddy currents are used in
Options
(a) Induction furnace (b) Electromagnetic breaks (c) Speedometers (d) All of these
Correct Answer:
Induction furnace
Explanation:
No explanation available. Be the first to write the explanation […]
The wing span of an aeroplane is 20 m. It is flying in a field where the vertical component of magnetic field of earth is 5×10⁻⁵ tesla with velocity 360 km/hour. The potential difference produced […]
An electric motor runs on DC source of emf 200 V and draws a current of 10 A. If the efficiency be 40%, then the resistance of armature is
Options
(a) 2Ω (b) […]
A transformer of 100% efficiency has 200 turns in the primary coil and 40000 turns in secondary coil. It is connected to a 220 V main supply and secondary feeds to a 100 kΩ resistance. […]
In an electrical circuit R,L,C and an AC voltage source are all connected in series. When L is removed from the circuit, the phase difference between the voltage and the current in the circuit is […]
If in a L-R series circuit the power factor is 1/2 and R=100Ω, then the value of L is, when AC mains is used
Options
(a) πH (b) √3/π H (c) π/√3 H (d) […]
The self-inductance of a choke coil is 10 mH. When it is connected with a 10 V DC source, then the loss of power is 20 W. When its is connected with 10 V AC […]
The power factor of an AC circuit having resistance R and inductance L connected in series to an AC source of angular frequency ω is
Options
(a) zero (b) ωL/R (c) R/√R²+ω²L² (d) R/ωL
An air core coil and an electric bulb are connected in series with an AC source. If an iron rod is put in the coil, then the intensity of light of the bulb will
For a series L-C-R circuit, the rms values of voltage across various components are Vʟ=90 V, Vᴄ=60V and Vʀ=40 V. The rms value of the voltage applied to the circuit is
Options
(a) […]
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