Question 2 : <p>Primary winding and secondary winding of a transformer has<br>100 and 300 turns respectively. If its input power is 60 W then output power of<br>the transformer will be</p>
Question 5 :
In an ideal parallel LC circuit, the capacitor is charged by connecting it to a DC source which is then disconnected. The current in the circuit
Question 6 :
What do we name the  device which increases the emf ?<br/>
Question 7 :
The correct formula for the angular frequency $\omega_0$ of an $L-C$ resonant circuit is
Question 8 :
A transformer steps up an $AC$supply from$220 V$to$2200V$. If the secondary coil of the transformer has$2000$turns, the number of turns in its primary coil will be:
Question 9 :
A transformer having $4000$ turns on its primary side and $500$ turns on the secondary side. If the input voltage is $240\ V$, find out the output voltage of the secondary side of the transformer ?
Question 10 :
In a transformer, the number of turns of primary coil and secondary coil are $5$and$4$respectively. If$220 V$isapplied on the primary coil, then the ratioof primary current to the secondary current is
Question 11 :
A transformer with a $110 V$ primary has a $15:1$ turns ratio. The load resistance, $R_L$, is $120$ . What is the approximate voltage across the load?<br/>
Question 13 :
The primary to secondary turns ratio of a transformer is given as 2 : 3. If the current through the primary coil is 3 A, then the current through load resistance is<br/>
Question 14 :
The ratio of the secondary to the primary turns in a transformer is $3:2$ and the output power is $P$. Neglecting all power losses, the input power must be:<span class="_wysihtml5-temp">
Question 15 :
Match the following<br/>a) step up transformer     d) turns ratio is 1<br/>b) step down transformer e) Ns > Np<br/>c) Ideal transformer           f) Np > Ns<br/>
Question 17 :
The ratio between the primary voltage and the secondary voltage in a transformer is equal to:<br/>
Question 19 :
The self inductance of the motor of an electric fan is 10 H. In order to impart maximum powr of 50 Hz, it should be connected to a capacitance of<br>
Question 20 :
A step up transformer converts $100$ V at primary to $300$ V at secondary.  If the primary current is $6$A, then the secondary current is ______A
Question 22 :
In an oscillating LC circuit the maximum charge on the capacitor is $Q$. The charge on capacitor when the energy is stored equally between electric and magnetic field is :
Question 24 :
For L-C-R, A.C circuit resonance frequency is $600Hz$ and frequencies at half power points are $550Hz$ and $650Hz$. What will be the Q-factor?
Question 25 :
In a step-down transformer the secondary coil has .............. number of turns.<br><br>
Question 27 :
In an R-C circuit, select the correct options among the following :<br/>
Question 28 :
The sinusoidal A.C. current flows through a resistor of resistance $R$. If the peak current is ${I}_{p}$, then power dissipated is
Question 29 :
In series $L-C-R$ circuit, the resonating frequency is 600 Hz.The half power points are at 650Hz and 550 Hz.The quality factor is:
Question 30 :
An inductance of $1mH$, a condenser of $10 \mu F$ and resistance of $50\Omega$ are connected in series. The reactance of inductor and condensers are same. The reactance of either of them will be:-
Question 32 :
When an a.c. source of e.m.f. $E={ E }_{ 0 }sin 100t$ is connected across a circuit, it is observed that voltage leads the current by a phase angle $\frac { \pi  }{ 4 } $. It the circuit consists possible only R-l, R-C or L-C in series the two elements could be:
Question 33 :
The ratio of turns in primary and secondary coils of a transformer is 1:10. The ratio of currents in primary and secondary coils will be
Question 34 :
An LC circuit has L$=$5 mH and C$=$20$\mu F $. $V=5\times 10^{-3}cos\omega t$ is supplied. $\omega$ is twice the resonant frequency. Find the maximum charge stored in the capacitor. <br/>
Question 35 :
A resistor and a capacitor are in series across a $20 V$ ac source. Circuit impedance is $4.33 k \Omega$. Current flow in the circuit is<br/>
Question 36 :
In non-resonant circuit, what will be the nature of the circuit for frequencies higher than the resonant frequency?
Question 37 :
Voltage across each elements of a series LCRcircuit are given by $V_L= 60V, V_C = 20V, V_R= 30V$Find out source voltage
Question 38 :
 In a series resonant L-C-R circuit, the voltage across R is 100 V and $R =1 k \, \Omega$ with $C = 2\mu F$. The resonant frequency is 200 $rads^{-1}$. At resonance the voltage across L is :<br/>
Question 39 :
The number of turns in the primary and secondary coils of a transformer are 100 and 300 respectively. If the input power is 60 watt the output power will be
Question 40 :
The quality factor of LCR circuit having resistance (R) andinductance (L) at resonance frequency $ (\omega) $ is given by
Question 41 :
The primary coil of a transformer is connected to a $60 V$ ac source. The secondary coil is connected to a $330$  load. The turns ratio is 3:1. What is the secondary voltage?<br/>
Question 42 :
The turning circuit of a radio receiver has a resistance of $50\ \Omega$, an inductor of $10\ \text{mH}$ and a variable capacitor. A $1\ \text{MHz}$ radio wave produces a potential difference of $0.1\ \text{mV}$. The values of the capacitor to produce resonance is (Take ${\pi}^{2}=10$):
Question 43 :
$A.C$. supply gives $30\ V\ r.m.s$. which passes through a $10\Omega$ resistance. The power dissipated in it is :
Question 44 :
Which of the following combinations should be selected for better tuning of an $LCR$ circuit used for communication?
Question 45 :
In an AC circuit voltage $V={ V }_{ 0 } \ sin \ wt$ and inductor L is connected across the circuit. Then the instentaneous power will be <br/>
Question 46 :
The values of $X_{L}, X_{C}$ and R in series with an A.C.  circuit are 8$\Omega $ , 6$\Omega $ and 10$\Omega $ respectively. The<br/>total impedance of the circuit will be ________$\Omega $<br/>
Question 47 :
Assertion: When capacitive reactance is smaller than the inductive reactance in $L-C-R$ circuit, emf leads the current.
Reason: The phase angle is the angle between the alternating emf and alternating current of the circuit.
Question 48 :
In series $LCR$ circuit, in the condition of resonance, if $C=1\mu F;L=1H$ then frequency will be:
Question 49 :
A coil has resistance $30 ohm$ and inductive reactance $20 ohm$ at $50 Hz$ frequency. If an $ac$ source of $200 volt, 100 Hz$, is connected across the coil, the current in the coil will be
Question 50 :
A $12$ ohm resistor and a $0.21$ henry inductor are connected in series to an AC source operating at $20volts$, $50$ cycle/second. The phase angle between the current and the source voltage is
