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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Q. The realization of a term K₀/s in the impedance function will give

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Q. An RL admittance function can also be realized as

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Q. In an R-C circuit, the impedance is 40 Ω at a frequency of 100 Hz. At 200 Hz the impedance should be

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Q. An RL series circuit has an impedance of 20 Ω when frequency is 25 Hz. At f= 50 Hz, the impedance will be

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Q. In active filters inductances are divided because they

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Q. Three resistance of 15 Ω each are connected in delta. The resistance of equivalent star will have a value of

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Q. In a varistor the v-i graph is linear.

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Q. The function Z(s) has a pole at infinity if

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Q. An input voltage V(t) = 10 √2 cos (t + 10°) + 10 √3 cos (2t + 10°)V is applied to a series combination of resistance R = 1 kΩ inductance L = 1H. The resulting steady-state current i(t) in ampere is

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Q. A thermal power plant has an efficiency of 0.4. If 0.6 kg of coal is burnt to generate 1 kWh, the calorific value of coal is

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