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A cylindrical wire is stretched to increase its length by 10%. Calculate the percentage increase in its resistance.
A solenoid with an iron core and bulb are connected to a dc source. how does the brightness of the bulb change when the iron core is removed from the solenoid.??? its urgent
what is wattless current?
what is the dimensional formulas of mutual inductance.
Two bodies of masses m1 and m2 are connected by a light string which passes over a frictionless massless pulley . If the pulley is moving upward with uniform acceleration g/2 , then tension in the string is - 1) 3 m1 m2 g / m1 + m2 ..............2)m1 + m2 g / 4m1 m2 ..........3)2 m1 m2 g / m1 + m2 ..............4)m1 m2 g / m1 + m2 ..............
what is meant by sharpness of resonance?
1. An electrical element X, when connected to an alternating voltage source, has the current through it leading the voltage by π/2 rad. Identify X and write an expression for its reactance.
2. Draw the graphs showing the variation of reactance of (a) a capacitor and (b) an inductor with the frequency of an a.c. circuit
define watt-less current?
A sinusoidal voltage of peak value 283 V and frequency 50 Hz is applied to a series LCR circuit in which R = 3 W, L = 25.48 mH, and C = 796 μF.
Find (a) the impedance of the circuit; (b) the phase difference between the voltage across the source and the current; (c) the power dissipated in the circuit; and (d) the power factor. In this question for finding P we use P=I^2 R and Irms=I/root2 but why do we divide 283 by 5?
why is 220v ac more dangerous then 22ov dc?
project to investigate the relation between the ratio of
1)output & input voltage
2)no. of turns in secondary & primary coil of a self designed transformer
A 200V variable frequency ac source is connected to series combination of
A reactive element , in an AC circuit causes the current flowing.
1. To lead by pi by two
2. to lag in phase by pi by two w.r.t. the applied voltage
Identify the element in each case.
plz answer this question :- A resistor of 200 ohm and a capacitor of 15 micro F are connected in series to a 220V, 50 Hz a.c. source . Calculate the current in the circuit and the r.m.s. voltage across the resistor and capacitor.
what is power factor in an a.c. circuit?
For circuits used for transporting electric power, a low power factor implies large power loss in transmission.Explain.
full form of LCR circuit?
what is the definition of quality factor
Power factor of an ac circuit is 0.5. What will be the phase difference between voltage and current in the circuit?
why does a capacitor block dc nd allows ac????
a bulb and a capacitor are connected in series to A.C.source of variable frequency.how will the brightness of the bulb change on increasing the frequency of the A.C. source? give reason for your answer.
wht is sharpness of resonance in series LCR- circuit ? a resistor of 200 ohm and capacitor of 15 muF
are connected in series 1:0 220V:50Hz ac sorce
a> calculate current in circuit
calculate voltage across resistor and capacitor. is the algebric sum of these voltages more than sorce voltage if yes how?
series LCR circuit
with L =
0.12 H, C =
480 nF, R =
23 Ω is connected to a 230 V variable frequency supply.
is the source frequency for which current amplitude is maximum.
Obtain this maximum value.
is the source frequency for which average power absorbed by the
circuit is maximum. Obtain the value of this maximum power.
which frequencies of the source is the power transferred to the
circuit half the power at resonant frequency? What is the current
amplitude at these frequencies?
What is the Q-factor
of the given circuit?
Show that in the free oscillations of an LC circuit, the sum of energies stored in the capacitor and the inductor is constant in time.
A 200v variable frequency a.c source is connected to a series combination of L=5H, e=80uF and R=40 ohms.Calculate:
a) angular frequency of the source to get max. current.
b) the current amplitude at resistance.
c) power dissipation in the circuit at resonance
d) Quality factor.
A series LCR circuit is connected to an A.C source of voltage V and angular frequency w.(omega.) When only the capacitor is removed, the current lags behind the voltage by a phase angle 'phi' and when only the inductor is removed , the current leads teh voltage by tha same phase angle. Find the current flowing and the average power dissipated in teh LCR circuit.? Please REply fast Please.
In an a.c circuit, instantaneous voltage and current are V=200sin300t volts and I=8cos300t Amp respectively. What is the average power dissipated in the circuit ? Why ?
what do you mean by Q-factor and whats is its importance ?
Why is the emf maximum when the plane of the armature is parallel to the magnetic filed in an ac generator ?
What is the function of a step up transformer.
The primary coil of an ideal step up transformer has 100 turn and transformation
what is the principle of METAL DETECTORS ?
how coswt = sin(wt+90) possible here??
An inductor 200 MH, capacitor 500µf, resistor 10Ω are connected in series with
Explain principle, working theory of Transformer.
in a series LCR circuit the voltages across an inductor,capacitor, n a resistor are 30V,30V n 60V respectively.wat is the phase difference b/w the applied voltage n current in the circuit.??
Give principle construction working of AC generator.
When an alternating voltage of 220V is applied across a device X, a current of 0.5A
flows through the circuit and is in phase with the applied voltage. When the same
voltage is applied across another device Y the same current flows through the
circuit but it leads the applied voltage by /2 rad.
(a) Name the devices X and Y.
(b) Calculate the current flowing in the circuit when same voltage is applied across
the series combinations of X and Y.
Q1.Show that in an ideal transformer when the voltage is stepped up by certain factor the current get stepped down by the same factor.
the current flowing through a pure inductor of inductance 4mH is i=12 cos 300 t ampere.what is the
i) rmsii) average value of the current for the complete cycle
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