EASY
Earn 100

In the circuit shown in figure, the current measured by ammeter is (Readings of voltmeter are as given)
V1=180 V,V2=300 V,V3=150 V

Question Image

50% studentsanswered this correctly

Important Questions on Alternating Current

EASY
A resistor R, an inductor L, a capacitor C and voltmeters V1,V2 and V3 are connected to an oscillator in the circuit as shown in the adjoining diagram. When the frequency of the oscillation is increased, then at the resonant frequency, the voltmeter reading is zero in the case of
Question Image
MEDIUM

Directions: Each of the following sentences in this section has a blank space and four words or group of words given after the sentence. Select the word or group of words you consider most appropriate for the blank space and indicate your response on the Answer Sheet accordingly.

Every rash driver becomes a ____ killer.

HARD
For a series RLC circuit R=XL=2XC. The impedance of the circuit and phase difference between V and I, respectively will be
HARD
An ideal choke draws a current of 8 A when connected to a source of 100 V, 50 Hz When a resistor is connected to the same source, it draws a current of 10 A. Now the choke and the resistor are connected in series and then connected to a source of 100 V, 40 Hz. The current in the circuit is
HARD
750 Hz, 20 Vrms source is connected to a resistance of 100 Ω, an inductance of 0.1803 H and a capacitance of 10 μF all in series. The time in which the resistance (heat capacity  2 J/°C ) will get heated by 10°C. (assume no loss of heat to the surroundings) is close to :
EASY
A series LCR circuit with R=43 Ω and L=0.5 H has a leading phase angle of 45° at a frequency of 50 Hz. The capacitance used in the circuit is
MEDIUM

A light bulb and an inductor coil are connected to an ac source through a key as shown in the figure below. The key is closed and after sometime an iron rod is inserted into the interior of the inductor. The glow of the light bulb

Question Image

HARD
The output voltage (taken across the resistance) of a LCR series resonant circuit falls to half its peak value at a frequency of 200 Hz and again reaches the same value at 800 Hz. The bandwidth of this circuit is:
EASY

Two sentences are given below and you are required to find the correct sentence which combines both the sentences.

Which is the correct combination of the given two sentences?

He is too tired. He could not stand.

MEDIUM
A seriesLCR  circuit is connected to an ac voltage source. When L is removed from the circuit, the phase difference between current and voltage is π3. If instead C is removed from the circuit, the phase difference is again π3 between current and voltage. The power factor of the circuit is:
MEDIUM

In the following sentence, a blank space with four options is given. Select whichever preposition or determiner you consider the most appropriate for the blank space.

These are the good rules to live _____.

HARD
A sinusoidal voltage of peak value 283 V and angular frequency 320 s-1 is applied to a series LCR circuit. Given that R=Ω, L=25 mH and C=1000 μF. The total impedance and phase difference between the voltage across the source and the current will respectively be-
HARD

When a 60 mH inductor and a resistor are connected in series with an AC voltage source, the voltage leads the current by 60°. If the inductor is replaced by a 0.5 μF capacitor, the voltage lags behind the current by 30°. What is the frequency of the AC supply?

MEDIUM
A charged capacitor of capacitance C is discharging through a resistor of resistance R. At what time the charge on the capacitor is equal to one half of its initial value?
MEDIUM
In a series LCR circuit with an alternating voltage source of frequency f, the current leads the voltage by 45°. The value of c is
HARD

The angular frequency of alternating current in a L-C-R circuit is 100 rad s-1. The components connected are shown in the figure. Find the value of inductance of the coil and capacity of condenser.

Question Image

EASY
An L.C.R. circuit contains resistance of 110 Ω and a supply of 220 V at 300 rad s-1 angular frequency. If only capacitance is removed from the circuit, current lags behind the voltage by 45°. If on the other hand, the only the inductor is removed the current leads by 45° with the applied voltage. The R.M.S. current flowing in the circuit will be:
MEDIUM
In a series circuit, R=300 Ω, L=0.9 H, C=2.0 μF and  ω=1000 rad s-1. The impedance of the circuit is 
MEDIUM
An arc lamp requires a direct current of 10 A at 80 V to function. If it is connected to a 220 V (rms), 50 Hz AC supply, the series inductor needed for it to work is close to:
EASY
A series R-C circuit is connected to an alternating voltage source. Consider two situations:

i. When capacitor is air filled.

ii. When capacitor is mica filled.

Current through resistor is i and voltage across capacitor is V then: