Q. Two voltages are 50 ∠0 V and 75 ∠ - 60° V. The sum of these voltages is

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Q. A magnetic circuit has an iron length of 20 cm and air gap length 0.1 cm. If μᵣ = 200 then

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Q. A circuit is fed by two sources of the same frequency and values 100 ∠0° V and 20 ∠30°V. The current in a particular branch is 5 ∠19° A. If the magnitudes of the sources and changed to 200 ∠0° V and 40 ∠30° V, the current in that branch should be

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Q. Two coils X and Y have self inductances of 5 mH and 10 mH and mutual inductance of 3 mH. If the current in coils X change at a steady rate of 100 A/s, the emf induced in coil Y is

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Q. Two capacitors of 2 μF and 4 μF capacitance are connected in series across a 30 V dc battery. After the capacitors have been charged, the voltage across them will be

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Q. A 50 Hz current has an amplitude of 10 A. The rate of change of current at t = 0.005 after i = 0 and is increasing is

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Q. In an air cored coil, a current of 0.7 A causes a flux of 5 x 10^-6 Wb. If the core is made of cast iron and the coil is similar, the same current can set up a flux of about

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Q. The self inductances of two coils are 27 H and 3 H. If the winding or coils is such that 50% of flux of one links the other, the mutual inductance is

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Q. In a lead acid cell, the positive plate has spongy lead.

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Q. For H(s) to be positive real, the condition Re[H(jω)] ≥ 0 for 0 ≤ ω ≤ ∞ is

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Q. A parallel plate capacitor with air as dielectric has a capacitance C. If the dielectric has a dielectric constant ∈ᵣ and the remaining dimensions are the same, the capacitance will be

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Q. Assertion (A): When excited by a unit step voltage, an inductor behaves as open circuit at t = 0.

Reason (R): Inductance has the property of inertia.

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Q. A bulb rated at 60 W, 120 V is used for 30 minutes. The charge associated with this operation is

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Q. Two coil have their axis perpendicular to each other. The coefficient of coupling k is

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Q. In a series RLC circuit, p-f is leading if XC < XL.

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Q. An RLC series circuit is fed form 100 V ac supply. Inductance is 1 H and Q = 7.5. At resonance, the voltage across inductance is

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Q. As temperature increases, the temperature coefficient of a metal

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Q. A wire has a resistance R ohm. If another wire of the same material and same weight has double the diameter (as compared to the first wire), the resistance of the second wire will be

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Q. When cells having different emfs are connected in parallel, a circulating current flows.

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Q. In a specimen of cast iron, a field strength of 400 AT/m cause a flux density of 0.6 T. In a specimen of silicon steel, the same value of H would cause B to be

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