Q. If Va = 10 ∠0, Vb = 10 ∠ -120° and Vc = 10 ∠ -240°, then Va2 and Va0 are

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Q. A wire has a diameter d and resistance R. If the diameter is made 3d, the length and material remaining the same, the new value of resistance will be

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Q. The realization of a reactance function gives

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Q. The correct relation between energy and charge is

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Q. Assertion (A): If A = 0.5 ∠ 20°, A² = 0.25 ∠ 40°.

Reason (R): When drawing a phasor diagram, sinusoids may have the same or different frequencies.

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Q. Which statement is incorrect for parallel resonance?

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Q. If a capacitor is charged by a square wave current source the voltage across the capacitor is

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Q. In an R-L-C series circuit, R = 2/√L/C . If R is doubled

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Q. A coil of resistance R and inductance L is connected in series with 10 mF capacitor. The resonant frequency is 1000 Hz. Another 10 F capacitor is connected in parallel with the above capacitor. The new resonance frequency will be

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Q. As the diameter of a wire is doubled, the resistance becomes

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Q. A series resonant circuit has R = 10 Ω, L = 1 μH and C = 1 mF. If R is increased to 20 Ω the resonant frequency

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Q. Assertion (A): Two terminal black boxes of R and C can be identified by plotting their static V-I characteristics.

Reason (R): The V-I characteristic of resistance is a straight line of slope R passing through origin.

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Q. The purpose of earthing electric appliances is

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Q. Three impedances (3 + j 4) Ω each are connected in star. The impedances of equivalent delta circuit will be

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Q. A heater is rated at 230 V, 5 A AC. Then

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Q. KCL is a statement of principle of conservation of energy.

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Q. One ampere means the flow of

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Q. When R and C are connected in parallel, phase angle of Y is positive.

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Q. A current of 1 A in the coil of an iron cored electromagnet causes B = 0.5T. If current is 2A, B =

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Q. Two current sources each of rms value 10 A have frequencies 40 Hz and 50 Hz respectively. They are connected in series, the expression for resultant wave is

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