Recent questions tagged medium

A transformer has 50 turns in the primary and 100 in the secondary . If the primary is connected to a $220\;v$ d.c supply . What will be the voltage across the secondary ?

asked Sep 27, 2016 by meena.p

1 answer

A 20 V , 750 Hz source is connected to a series combination of $R= 100\; \Omega, C= 10 \mu F $ and $L= 0.1803\;H$ . Calculate the time in which resistance will get heated by $10^{\circ}$ if thermal capacity of the material $=25 \%$

asked Sep 27, 2016 by meena.p

1 answer

Two different coils have self inductance $L_1=8\;mH$ and $L_2=2\;mH$. At a certain instant , the current in the two coils is increasing at the same constant rate and the power supplied to the two coils is the same . Find the ratio of the current and energy stored.

asked Sep 27, 2016 by meena.p

1 answer

Two different coils have self inductance $L_1=8\;mH$ and $L_2=2\;mH$. At a certain instant , the current in the two coils is increasing at the same constant rate and the power supplied to the two coils is the same . Find the ratio of induced voltage at that instant

asked Sep 27, 2016 by meena.p

1 answer

1 Mw power is to be delivered from a power station to a town $10\;km$ away. One uses a pair of cer wires $0.5\;cm$ for this purpose . Calculate the fraction of ohmic losses to power transmitted if power is transmitted comment on the feasibility of doing this ?

asked Sep 27, 2016 by meena.p

1 answer

An electrical drive draws 2 kw power from AC mains [ Voltage $223 V(rms) = \sqrt {50,000}\;v$ ]. The current differs (lags) in phase by $\phi (\tan \phi = -\large\frac{-3}{4} )$ as compared to voltage . Find $I_{max}$ another device has twice the value of $R,X_c$ and $X_L$. How are the answers affected ?

asked Sep 27, 2016 by meena.p

1 answer

I buy 10 boxes of mangoes each box weighing 5 Kgs. I also buy 5 boxes of apples, each box weighing 10 Kgs. I pay a total of Rs. 281.90. I store them in a freezer and consume 1/2 a Kg every day. How long does it take me to finish all the fruits?

asked Sep 26, 2016 by balaji.thirumalai

1 answer

An electrical drive draws 2 kw power from AC mains [ Voltage $223 V(rms) = \sqrt {50,000}\;v$ ]. The current differs (lags) in phase by $\phi (\tan \phi = -\large\frac{-3}{4} )$ as compared to voltage . Find $ X_C - X_L$

asked Sep 26, 2016 by meena.p

1 answer

An electrical drive draws 2 kw power from AC mains [ Voltage $223 V(rms) = \sqrt {50,000}\;v$ ]. The current differs (lags) in phase by $\phi (\tan \phi = -\large\frac{-3}{4} )$ as compared to voltage . Find R

asked Sep 26, 2016 by meena.p

1 answer

A $60\;w$ load is connected to the secondary of a transformer whose primary draws line voltage. If a current of $0.54\;A$ flows in the load, what is the current in the primary coil ? Comment on the type of transformer bring used ?

asked Sep 26, 2016 by meena.p

1 answer

A Coil of $0.01$ Henry inductance and 1 ohm resistance is connected to $200 \;volt,50 Hz,ac $ supply . Find the impedance of the circuit and time lag between max. alternating voltage and current .

asked Sep 26, 2016 by meena.p

1 answer

How does the sign of the phase angle $\phi$ , big which the supply voltage leads the current in an LCR series circuit , change as the supply frequency is gradually increased from very low to very high values ?

asked Sep 23, 2016 by meena.p

1 answer

Can the instantaneous power output of an ac source ever he negative ? can the average power output be negative ?

asked Sep 23, 2016 by meena.p

1 answer

For an LCR circuit , the power transferred forms the diving source to the drives oscillator is $P= I^2 z \cos \phi$

asked Sep 22, 2016 by meena.p

1 answer

An inductor of a reactance $1 \Omega$ and a resistor of $2 \Omega$ are connected in series to the terminals of a$6\;v(r.m.s)$ a.c source. The power dissipated in the circuit is

asked Sep 22, 2016 by meena.p

1 answer

Which of the following combination should be selected for better turning of an LCR circuit used for communication ?

asked Sep 21, 2016 by meena.p

1 answer

The voltmeter the resonant frequency in an L.C.R series circuit with a generator .

asked Sep 21, 2016 by meena.p

1 answer

When a voltage measuring device is connected to AC mains , the meter shows the steady input voltage opf $220\;v$ This means

asked Sep 21, 2016 by meena.p

1 answer

An alternating current generator has an internal resistance $R_g$ and an internal reluctance $X_g$.It is used to supply power to a passive loud consisting of a resistance $R_g$ and a reluctance $x_L$ . For maximum power to be delivered from the generator to the load, the value of $X_L$ is equal to

asked Sep 21, 2016 by meena.p

1 answer

If the rms current in a 50 Hz a.c circuit is $5\;A$ , the value of the current $ \large\frac{1}{300}$ seconds after its value becomes zero is

asked Sep 21, 2016 by meena.p

1 answer

At a hydroelectric power plant , the water pressure head is at a height of 300 m and the water flow available is $100 m^3 s^{-1} $. If the turbine generator efficiency is $60\%$ estimate the electric power available from the plant $(g= 9.8 ms^{-2})$

asked Sep 20, 2016 by meena.p

1 answer

Why is choke coil needed in the use of flourscent takes with a.c mains? Why can we not use an ordinary resistor instead of choke coil ?

asked Sep 20, 2016 by meena.p

1 answer

A check coil in series with a lamp is connected to a d.c line. The lamp is seen to shine brightly and insertion of an iron core in the choke causes no change in the lamps brightness. Predict the corresponding observation if the connection is to as a.c line

asked Sep 20, 2016 by meena.p

1 answer

An applied voltage signal consists of a super position of a d.c voltage and a.c voltage of high frequency . The circuit consists of an inductor and a capacitor in series. will the d.c signal will appear across c and the a.c signal will appear across L ? At high frequencies

asked Sep 20, 2016 by meena.p

1 answer

Obtain the resonant frequency and Q- factor of a series circuit with $L= 3.0 \;H,C= 27\mu F$ and $R= 7.4 \Omega$ . It is desired to improve the sharpness of resonance of the circuit by reducing its full width at half max. by a factor of 2. suggest a suitable way

asked Sep 20, 2016 by meena.p

1 answer

A series LCR circuit with $L= 0.12 H,C= 480\;nF,R= 23 \Omega $ is connected to a $230\;v$ variable frequency supply .For What frequencies of the circuit half the power at resonant frequency . What is the Q factor of the given circuit ?

asked Sep 19, 2016 by meena.p

1 answer

A series LCR circuit with $L= 0.12 H,C= 480\;nF,R= 23 \Omega $ is connected to a $230\;v$ variable frequency supply .For What frequencies of the circuit half the power at resonant frequency . What is the current amplitute at these frequencies?

asked Sep 19, 2016 by meena.p

1 answer

A series LCR circuit with $L= 0.12 H,C= 480\;nF,R= 23 \Omega $ is connected to a $230\;v$ variable frequency supply .What is the source frequency for which average power absorbed by the circuit is maximum ? obtain the value of this mass power

asked Sep 19, 2016 by meena.p

1 answer

A series LCR circuit with $L= 0.12 H,C= 480\;nF,R= 23 \Omega $ is connected to a $230\;v$ variable frequency supply .

asked Sep 19, 2016 by meena.p

1 answer

Suppose a circuit containing 80 mH and a $60 \mu F$ capacitor in series is connected to a $230\;V, 50 \;Hz$ Supply . The resistance in the circuit is negligible . obtain the average power transferred to each element of the circuit , and the total power absorbed .

asked Sep 19, 2016 by meena.p

1 answer

A circuit containing a $80\;mH$ inductor and a $60 \mu F$ capacitor in series is connected to a $230\;v,50\;Hz$ supply . The resistance in the circuit is negligible. obtain the current amplitude and V.M.S value of potential drop across each element .

asked Sep 16, 2016 by meena.p

1 answer

A circuit containing a $80\;mH$ inductor and a $60 \mu F$ capacitor in series is connected to a $230\;v,50\;Hz$ supply . The resistance in the circuit is negligible. obtain the current amplitude and V.M.S value

asked Sep 15, 2016 by meena.p

1 answer

Keeping the source frequency equal to the resonating frequency of the series LCR circuit , if the three elements L,C and R , an arranged in parallel , show that the total current in the parallel LCR circuit, is a minimum at this frequency . obtain the r.m.s value of current in each branch of the circuit for the elements and source whose values are $L= 5.0 \;H,C= 80\;\mu F, R= 40 \Omega$ for this frequency

asked Sep 15, 2016 by meena.p

1 answer

A $100 \mu F$ capacitor in series with a $40 \Omega$ resistance is connected to a $110\;V,60Hz$ supply , What is the time lag between maximum and voltage maximum ?

asked Sep 15, 2016 by meena.p

1 answer

A $100 \mu F$ capacitor in series with a $40 \Omega$ resistance is connected to a $110\;V,60Hz$ supply , What is the maximum current in the circuit ?

asked Sep 15, 2016 by meena.p

1 answer

A coil of inductance $0.50\;H$ and resistance $100 \Omega$ is connected to a $240\;v,50\;Hz$ a.c supply What is the time lag between the voltage maximum and current maximum?

asked Sep 14, 2016 by meena.p

1 answer

A coil of inductance $0.50\;H$ and resistance is connected to a $240\;v,50\;Hz$ a.c supply What is the maximum current in the coil ?

asked Sep 14, 2016 by meena.p

1 answer

An LC circuit a $20\;mH$ inductor and a $50 \mu F$ capacitor with an initial charge of $10\;mc$ The resistance of the circuit is negligible. if a resistor is inserted in the circuit , how many energy is eventually dissipated as heat ?

asked Sep 14, 2016 by meena.p

1 answer

An LC circuit a $20\;mH$ inductor and a $50 \mu F$ capacitor with an initial charge of $10\;mc$ The resistance of the circuit is negligible. Let the instant the circuit is closed be $t=0$, At what time is the total energy should equally between the inductor and the capacitor?

asked Sep 14, 2016 by meena.p

1 answer

An LC circuit a $20\;mH$ inductor and a $50 \mu F$ capacitor with an initial charge of $10\;mc$ The resistance of the circuit is negligible. Let the instant the circuit is closed be $t=0$, At what time is the energy stored ? (i) Completely electrical? (ii) Completely magnetic ?

asked Sep 12, 2016 by meena.p

1 answer

An LC circuit a $20\;mH$ inductor and a $50 \mu F$ capacitor with an initial charge of $10\;mc$ The resistance of the circuit is negligible. Let the instant the circuit is closed be $t=0$, What is the natural frequency of the circuit ?

asked Sep 12, 2016 by meena.p

1 answer

An LC circuit a $20\;mH$ inductor and a $50 \mu F$ capacitor with an initial charge of $10\;mc$ The resistance of the circuit is negligible. Let the instant the circuit is closed be $t=0$, What is the total energy stored initially ? Is it conserved during the oscillations ?

asked Sep 12, 2016 by meena.p

1 answer

A series LCR circuit connected to a variable frequency $230\;v$ Source has $L= 5.0\;H,c=80 \mu F,R= 40 \Omega$ as shown in the figure. Determine the r.m.s potential drops across the three elements of the circuit . What is the potential drop across the LC combination at the resonating frequency .

asked Sep 12, 2016 by meena.p

1 answer