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**Description :** A (solenoid) coil is wound on a core of square cross-section. If all the linear dimensions of core are increased 2 times, but the number of turns per unit length of the coil, remains same, the self inductance would increases by a factor of (1) 2 (2) 4 (3) 8 (4) 16

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**Description :** If the permeability of the core of a coil increases, what happens to (a) inductance and (b) true power in the circuit?

**Last Answer :** (a) Inductance increases; (b) true power decreases.

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**Description :** If inductance increases in a series LR circuit, what happens to true power?

**Last Answer :** It decreases.

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**Description :** The inductance of a power transmission line increases with (A) decrease in line length. (B) increase in conductor diameter. (C) increase in spacing between phase conductors. (D) increase in load current carried by conductors.

**Last Answer :** The inductance of a power transmission line increases with increase in spacing between phase conductors.

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**Description :** An LCR series circuit, with resistance 100Ω is connected to an a.c. source of 200 V and angular frequency 300 rad/s. When the capacitance is removed from the circuit, current lags behind the ... removed from the circuit, the current leads the voltage by 600 . Calculate the current in the circuit.

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**Description :** An a.c. source of frequency 50 Hz is applied to a series circuit of resistance 20Ω , an inductance of 100 mH and a capacitance of 30μF . Does the current lag or lead the applied voltage? If so, by what (phase) angle?

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**Description :** A sinusoidal A.C. voltage source, of adjustable frequency, is connected across a series LCR' combination. The inductance (L) and the capacitance (C), present in the circuit, can be expresssed in terms of the quality factor (Q) the ... \(L=\frac{1}{ω_0Q^2R^2}\) and \(C = (\frac{Q^2R^2}{ω_0})\)

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**Description :** The inductance, capacitance and resistance in a given series LCR circuit, have values of (n) henry, (1/n3) farad and (n2) ohm. The quality factor, Q, and the resonant frequency (v0) , of this circuit, equal, respectively, (1) \(Q=\ ... frac{2\pi}{n}\) (4) \(Q=\frac{8\pi^2}{n^2}; v_0=\frac{4\pi}{n}\)

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**Description :** Which of the following statements concerning AC circuits is correct? A. The power factor of a resistive circuit is always zero. B. True power in an inductive circuit always equals apparent power. ... . D. Total opposition to the flow of alternating current depends upon the amount of reactive power.

**Last Answer :** Answer: C

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**Description :** An increase in which of the listed conditions will increase the speed of a synchronous motor? A. Frequency B. Voltage C. Armature current D. Inductance

**Last Answer :** Answer: A

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**Description :** If the length of a Hertz dipole is decreased A. its resonant frequency will be lowered its distributed inductance will be increased B. its distributed inductance will be decreased C. its ... frequency will be increased D. its distributed capacitance between the antenna and ground will be increased.

**Last Answer :** C. its resonant frequency will be increased

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**Description :** Refers to an ac bridge for measuring the inductance and Q of an inductor in terms of resistance, frequency and a standard capacitance.

**Last Answer :** hay bridge

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**Description :** An a.c series circuit has resistance of 10ohm, inductance of 0.1H and capacitance of 10µf, voltage applied to circuit is 200V. find (i) Resonant frequency (ii) Current at resonance (iii) Power at resonance

**Last Answer :** Solution: For RLC series circuit

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**Description :** effect of inductance and capacitance on performance of transmission line.

**Last Answer :** Following are the effect on performance of transmission line: 1. Due to inductance (L) voltage drop in transmission line produces. 2. Capacitor (C) draws charging current ... , transmission line efficiency, voltage regulation & also power factor of transmission line gets affected.

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**Description :** What is inductance?

**Last Answer :** Inductance is the property of Material by which it opposes the any change of magnitude or direction of electric current passing through the conductor. The inductance is denoted by L. The unit of inductance is Henry (H).

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**Description :** Self induced voltage across an inductance

**Last Answer :** Self induced voltage across an inductance

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**Description :** State the effects of errors in dynamometer type wattmeter due to i) pc- inductance ii) pc- capacitance iii) mutual inductance iv) Connection.

**Last Answer :** Errors in wattmeter: i) pc - inductance: Pressure coil inductance causes wattmeter to read more power than actual . ii) pc-capacitance: The wattmeter reads less power. iii) ... iv) Connection: In uncompensated wattmeter , the reading of wattmeter includes the powerloss in coils.

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**Description :** Describe with working of LCR meter for measurement of inductance.

**Last Answer :** working of LCR:- A LCR meter (Inductance (L), Capacitance (C), and Resistance (R) test equipment used to measure the inductance, capacitance and, resistance of a component. It works on the ... in parallel (as would be encountered in measuring a capacitor with a leaky dielectric) [Q setting ]

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**Description :** Define :i) Self inductance ii) Coefficient of self induction

**Last Answer :** i) Self-inductance: It is the property by virtue of which a coil opposes change in current flowing through it by inducing an emf in it such that its effect is to circulate current (induced current) that produces a magnetic field ... N = di/dt N = Φ/I It is expressed in henry.

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**Description :** A coil of 500 turns is linked with a flux of 25 mwb, when carries a current of 12.5A. Calculate the value of self-inductance.

**Last Answer :** Ans: Self-Inductance: L = NΦ /I = 500 × 25 × 10-3 / 12.5 = 1 H

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**Description :** In practice, a current source inverter consists of an AC/ DC converter with a large inductance ‘L’ in the output. This inductance maintains a ……… …………through the switching devices over short interval of time. A) constant current B) constant voltage C) constant power D) none of the (A), (B), (C)

**Last Answer :** In practice, a current source inverter consists of an AC/ DC converter with a large inductance ‘L’ in the output. This inductance maintains a constant current through the switching devices over short interval of time.

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**Description :** An iron cored inductance coil can be modelled, over a normal operating range of networks ,as A) non-Linear bilateral element B) linear bilateral element C) linear time varying element D) non-linear time invariant element

**Last Answer :** An iron cored inductance coil can be modelled, over a normal operating range of networks ,as linear bilateral element

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**Description :** These self inductance of a circuit is defined as twice the work done against the induced e.m.f. on establishing unit current in the coil. If the current to be established in the coil is doubled, the work done ... induced e.m.f. will be 1. Doubled 2. Halved 3. four times 4. Quarter times

**Last Answer :** These self inductance of a circuit is defined as twice the work done against the induced e.m.f. on establishing unit current in the coil. If the current to be established in the coil is doubled, the work done against the induced e.m.f. will be four times

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**Description :** lt the length, number of turns and area of a coil are doubled, the inductance of the coil

**Last Answer :** lt the length, number of turns and area of a coil are doubled, the inductance of the coil is quadrupled

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**Description :** A coil of inductance 240 mH and resistance 75 Ohm is connected in parallel with a capacitor across a 30 V, variable frequency supply. The current drawn by the circuit is found to be minimum when the supply frequency is 1 kHz. The ... (A) 40, 400 Hz (B) 10, 100 Hz (C) 20, 50 Hz (D) 50, 20 Hz

**Last Answer :** A coil of inductance 240 mH and resistance 75 Ohm is connected in parallel with a capacitor across a 30 V, variable frequency supply. The current drawn by the circuit is found to be minimum ... supply frequency is 1 kHz. The approximate values of Q-factor and bandwidth are, respectively 20, 50 Hz

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**Description :** A network consists of several inductances connected in parallel. The equivalent inductance of the network is given by (A) the sum of the individual inductances. (B) the reciprocal of the ... of individual inductances. (D) the reciprocal of the sum of reciprocals of individual inductances.

**Last Answer :** A network consists of several inductances connected in parallel. The equivalent inductance of the network is given by the reciprocal of the sum of reciprocals of individual inductances.

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**Description :** What is the value of Inductance of a coil that induces 20 V when the current through the coil changes from 12 to 20 A in 2 seconds? A. 2 H B. 3 H C. 4 H D. 5 H

**Last Answer :** 5 H is the value of Inductance of a coil that induces 20 V when the current through the coil changes from 12 to 20 A in 2 seconds.

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**Description :** A 220 kV, 3 phase transmission line is 60 km long. The resistance is 0.15 ohm / km and the inductance is 1.4 mH / km. Use the short line model to find the power at the sending end when the line is supplying a three ... at 0.8 pf lagging at 220 kV. (A) 5.58MW (B) 80MW (C) 85.58MW (D) 74.42 MW

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**Description :** A parallel combination of capacitance C and resistance R is connected in series with inductance L and small resistance r. Under what condition will the circuit be non-reactive? (A) C=LR (B) C=LR2 (C) C=L/R2 (D) C=L/R

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**Description :** The current i(t), through a 10 Ω resistor in series with an inductance, is given by I(t) = 3 + 4sin (100t + 450 ) + 4 sin(300t +600) amperes. The RMS values of the current and power dissipation ... respectively (B) √35 A, 350 W respectively (C) 5 A, 250 W respectively (D) 11 A, 1210 W respectively

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**Description :** A three phase 50 Hz, 400 kV transmission line is 300 km long. The line inductance is 0.97 mH/km per phase and capacitance is 0.0115 mF/km per phase. Assume a loss less line. Determine the line wavelength (a line phase constant). (A) 1250 km (B) 6578 km (C) 4990 km (D) 2445 km

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**Description :** A choke coil having resistance RΩ and of inductance L Henry is shunted by a capacitor of C farads. The dynamic impedance of the resonant circuit would be: (A) R/LC (B) C/RL (C) L/RC (D) 1/RLC

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**Description :** The differential coupling of two coils in series connection has self-inductance of 2 mH & 4 mH & a mutual inductance of 0.15 mH. The equivalent inductance of the combination is: (A) 5.7 mH (B) 5.85 mH (C) 6 mH (D) 6.15 mH

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**Last Answer :** An undesirable side effect of motional inductance of large conduction specimens is eddy currents.

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**Description :** A series RLC circuit has a resistance of 50 , inductance of 0.4H and a capacitor of 10µF. The circuit is connected across a 100V supply. The resonance frequency and the current through the resistance are

**Last Answer :** A series RLC circuit has a resistance of 50 , inductance of 0.4H and a capacitor of 10µF. The circuit is connected across a 100V supply. The resonance frequency and the current through the resistance are 500 rad/s and 2A.

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**Description :** Two similar coils have self inductance of 1 mH each. Coefficient of coupling is 0.5. The mutual inductance M is

**Last Answer :** Two similar coils have self inductance of 1 mH each. Coefficient of coupling is 0.5. The mutual inductance M is 0.5 mH.

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**Description :** The initial rate of rise of current through a coil of inductance 10 H when suddenly connected to a D.C. supply of 200 V is_______Vs.

**Last Answer :** The initial rate of rise of current through a coil of inductance 10 H when suddenly connected to a D.C. supply of 200 V is 20 Vs

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**Description :** When both the inductance and resistance of a coil are doubled the value of?

**Last Answer :** When both the inductance and resistance of a coil are doubled the value of time constant remains unchanged.

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**Description :** The inductance of a coil can be increased by?

**Last Answer :** The inductance of a coil can be increased by choosing core material having high relative permeability.

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**Description :** If resistance is 20 Q. and inductance is 27 in a R-L series circuit, then time constant of this circuit will be?

**Last Answer :** 0.1s

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**Description :** Inductance of coil?

**Last Answer :** Inductance of coil increases with the increase in supply frequency.

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**Description :** Inductance of a coil Varies?

**Last Answer :** Inductance of a coil Varies as directly as the cross-sectional area of magnetic core and inversely as the length of the iron path.

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**Description :** Inductance affects the direct current flow?

**Last Answer :** Inductance affects the direct current flow at the time of turning on and off.

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**Description :** In series resonant circuit, increasing inductance to its twice value and reducing capacitance to its half value?

**Last Answer :** In series resonant circuit, increasing inductance to its twice value and reducing capacitance to its half value will increase the selectivity of the circuit.

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**Last Answer :** Resistance: This could be defined as the opposition or retarding force to the flow of current in a circuit. It is measured in Ohms. Capacitance: The ability of a system of electrical conductors and insulators ... due to a rate of change of current in the circuit or coil. It's unit is Henry.

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