AC Generator & Transformer

A step down transformer has $50$ turns on secondary and $1000$ turns on primary winding. If a transformer is connected to $220$ V and $1$ A a.c. source, what is the output current of the transformer?

A transformer has 120 turns in the primary coil and carries 5A current. Input power is one kilowatt. To have 560 V output, the number of turns in secondary coil will be

A step down transformer has turns ratio 20:1. If 8V are applied across $0.4\ \Omega$ secondary then the primary current will be

An ideal transformer converts $220$V a.c. to $3.3$ KV a.c. to transmit a power of $4.4$ KW. If primary coil has $600$ turns then alternating current in the secondary coil is

The output of step-down transformer is measured to be $36$ V when connected to $6$ W light bulb. The value of peak current is

If a transformer of an amplifier has output impedance $8000\ \Omega$ and the speaker has input impedance of $8\ \Omega$, the primary and secondary turns of this transformer connected between the output of amplifier and to loudspeaker should have the ratio

Alternating current of peak value $\left(\frac{2}{\pi}\right)$ A flows through the primary coil of a transformer. The coefficient of mutual inductance between primary and secondary coils is 1H. The peak value of induced e.m.f. in the secondary coil is

(Frequency of a.c. = 50 Hz)

A transformer having an efficiency 80% is working on $200$ V and $4$ kW power supply. If the current in the secondary coil is $5$ A, the voltage across the secondary coil and the current in the primary coil, respectively, are

A current of $5$ A is flowing at $220$ V in the primary coil of a transformer. If the voltage produced in the secondary coil is $2200$ V and $50\%$ of power is lost, then the current in secondary will be

A transformer having efficiency $90\%$ is working on $200$ V and $3$ KW power supply. If the current in the secondary coil is $6$A, the voltage across the secondary coil and the current in the primary coil, respectively, are

A current of 4 A is flowing at 230 V in the primary coil of a transformer. If the voltage produced in the secondary coil is 2300 V and 40 % of power is lost, then the current in the secondary will be

An ideal transformer converts 220 a.c. to 3.3 kV a.c. to transmit a power of 4.4 kW. If primary coil has 600 turns then alternating current in secondary coil is

A current of 5 A is flowing at 220 V in a primary coil of a transformer. If the voltage produced in the secondary coil is 2200 V and $50\%$ of power is lost, then the current in the secondary coil will be

A transformer has 120 turns in the primary coil and carries 5 A current. Input power is one kilowatt. To have 560 V output, the number of turns in secondary coil will be

A transformer is used to set up an alternating e.m.f. of 220 V to 4.4 kV to transmit 6.6 kW of power. The primary coil has 1000 turns. The current rating of the secondary coil is (Transformer is ideal)

A step up transformer is connected to an ac mains supply of $220\text{ V}$ to operate at $11000\text{ V},\ 88$ watt. The current in the secondary circuit, ignoring the power loss in the transformer, is

In an ideal transformer, the turns ratio is $\frac{N_P}{N_S} = \frac{1}{2}$. The ratio $V_S : V_P$ is equal to (the symbols carry their usual meaning):

Primary coil of a transformer is connected to $220\text{ V}$ ac. Primary and secondary turns of the transformer are 100 and 10 respectively. Secondary coil of transformer is connected to two series resistances shown in figure. The output voltage $(V_0)$ is:

The core used in transformers are laminated to

The core used in transformer and other electromagnetic devices is laminated to

A transformer has an efficiency of $80\%$ and works at $10\text{ V}$ and $4\text{ kW}$. If the secondary voltage is $240\text{ V}$, then the current in the secondary coil is:

If a transformer of an audio amplifier has output impedance $8000\,\Omega$ and the speaker has input impedance $8\,\Omega$, the primary and secondary turns of this transformer connected between the output of amplifier and to loudspeaker should have the ratio

Alternating current of peak value $\left(\frac{2}{\pi}\right)$ A flows through the primary coil of a transformer. The coefficient of mutual inductance between primary and secondary coils is 1 H. The peak e.m.f. induced in secondary coil (Frequency of a.c. $= 50\text{ Hz}$)

Primary side of a transformer is connected to $230\text{ V},\ 50\text{ Hz}$ supply. Turns ratio of primary to secondary winding is $10 : 1$. Load resistance connected to secondary side is $46\,\Omega$. The power consumed in it is:

A transformer having efficiency $90\%$ is working on 200 V and 3 kw power supply. If the current in the secondary coil is 6 A, the voltage across the secondary coil and the current in the primary coil are respectively

A power transmission line feeds input power at $2.3\text{ kV}$ to a step down transformer with its primary winding having 3000 turns. The output power is delivered at $230\text{ V}$ by the transformer. The current in the primary of the transformer is $5\text{ A}$ and its efficiency is $90\%$. The winding of transformer is made of copper. The output current of transformer is _________ $A$.

The coil of an a.c. generator has 100 turns, each of cross-sectional area $2\text{ m}^2$. It is rotating at constant angular speed $30\text{ rad/s}$, in a uniform magnetic field of $2 \times 10^{-2}\text{ T}$. If the total resistance of the circuit is $600\ \Omega$ then maximum power dissipated in the circuit is

Match List - I with List - II:

Choose the correct answer from the options given below:

In an ac generator, a rectangular coil of 100 turns each having area $14 \times 10^{-2}\text{ m}^2$ is rotated at $360\text{ rev/min}$ about an axis perpendicular to a uniform magnetic field of magnitude $3.0\text{ T}$. The maximum value of the emf produced will be ________ $V$.

$($ Take $\pi = \frac{22}{7})$

The number of turns in the primary and the secondary of a transformer are 1000 and 3000, respectively. If $80\text{ V AC}$ is applied to the primary coil of the transformer, then the potential difference per turn of the secondary coil would be

A $12\text{ V},\ 60\text{ W}$ lamp is connected to the secondary of a step down transformer, whose primary is connected to ac mains of $220\text{ V}$. Assuming the transformer to be ideal, what is the current in the primary winding?

A square shaped coil of area $70\text{ cm}^2$ having 600 turns rotates in a magnetic field of $0.4\text{ wbm}^{-2}$, about an axis which is parallel to one of the sides of the coil and perpendicular to the direction of field. If the coil completes 500 revolutions in a minute, the instantaneous emf when the plane of the coil is inclined at $60^\circ$ with the field, will be ____________ V. (Take $\pi = \frac{22}{7}$)

An ideal transformer with purely resistive load operates at $12\text{ kV}$ on the primary side. It supplies electrical energy to a number of nearby houses at $120\text{ V}$. The average rate of energy consumption in the houses served by the transformer is 60 $\text{kW}$. The value of resistive load $(\text{Rs})$ required in the secondary circuit will be ___________ $\text{m}\Omega$.

Match List-I with List-II.

Choose the correct answer from the options given below:

A transformer operating at primary voltage $8\text{ kV}$ and secondary voltage $160\text{ V}$ serves a load of $80\text{ kW}$. Assuming the transformer to be ideal with purely resistive load and working on unity power factor, the loads in the primary and secondary circuit would be

Match List I with List II.

Choose the correct answer from the options given below:

A step up transformer operates on $220\text{ V}$ and supplies current of $2\text{ A}$. The ratio of primary and secondary windings is $1 : 20$. The current in the primary is

A step down transformer has turns ratio $20 : 1$. If $8\text{ V}$ is applied across $0.4\text{ ohm}$ secondary then the primary current will be

In a step up transformer, which one of the following statements is correct?

In an ideal step down transformer, out of the following quantities, which quantity increases in the secondary coil?

A step down transformer connected to an ac mains supply of 220 V is made to operate at 11 V, 44W lamp. Ignoring power losses in the transformer, what is the current in the primary circuit?

For the given circuit, comment on the type of transformer used.

A step down transformer is used to reduce the main supply from '$V_1$ ' volt to '$V_2$ ' volt. The primary coil draws a current '$I_1$' $\text{A}$ and the secondary coil draws '$I_2$ ' A. $(I_1 < I_2)$. The ratio of input power to output power is

A common transistor radio set requires 12 V (D.C.) for its operation. The D.C. source is constructed by using a transformer and a rectifier circuit, which are operated at 220 V (A.C.) on standard domestic A.C. supply. The number of turns of secondary coil are 24, then the number of turns of primary are ___________.

A step-up transformer has 300 turns of primary winding and 450 turns of secondary winding. A primary is connected to 150 V and the current flowing through it is 9A. The current and voltage in the secondary are

A 220 V input is supplied to a transformer. The output circuit draws a current of 2.0 A at 440 V. If the ratio of output to input power is 0.8, then the current drawn by primary winding is

A transformer consisting of 300 turns in the primary and 150 turns in the secondary gives output power of 2.2 kW. If the current in the secondary coil is 10A, then the input voltage and current in the primary coil are:

A power transmission line feeds input power at 2300 V to a step down transformer with its primary windings having 4000 turns. The output power is delivered at 230 V by the transformer. If the current in the primary of the transformer is 5A and its efficiency is 90%, the output current would be:

A power transmission line feeds input power at 2300 V to a step down transformer with its primary windings having 4000 turns, giving the output power at 230 V. If the current in the primary of the transformer is 5 A, and its efficiency is 90%, the output current would be;

A transformer having efficiency of 90% is working on 200 V and 3 kW power supply. If the current in the secondary coil is 6 A, the voltage across the secondary coil and the current in the primary coil respectively are

The primary of a transformer when connected to a dc battery of 10 Volt draws a current of 1 mA. The number of turns of the primary and secondary windings are 50 and 100 respectively. The voltage in the secondary and the current drawn by the circuit in the secondary are respectively

A 220 volt input is supplied to a transformer. The output circuit draws a current of 2.0 ampere at 440 volts. If the efficiency of the transformer is 80%, the current drwn by the primary windings of the transformer is

A transformer is used to light a 100 W and 110 V lamp from a 220 V mains. If the main current is 0.5 amp, the efficiency of the transformer is approximately

The primary and secondary coils of a transformer have 50 and 1500 turns respectively. If the magnetic flux $\phi$ linked with the primary coil is given by $\phi = \phi$0 + 4t, where $\phi$ is webers, t is time in seconds and $\phi$0 is a constant, the output voltage across the secondary coil is

In an $AC$ generator, a coil with $N$ turns, all of the same area $A$ and total resistance $R,$ rotates with frequency $\omega$ in a magnetic field $B.$ The maximum value of $emf$ generated in the coil is

The core of a transformer is laminated because

The core of any transformer is laminated so as to

In a transformer, number of turns in the primary coil are $140$ and that in the secondary coil are $280.$ If current in primary coil is $4A,$ then that in the secondary coil is

A step-up transformer operates on a $230\text{ V}$ line and supplies current of $2\text{ A}$ to a load. The ratio of the primary and secondary windings is $1 : 25$. The current in the primary coil is

The primary winding of a transformer has 500 turns whereas its secondary has 5000 turns. The primary is connected to an A.C. supply 20 V, 50 Hz. The secondary will have an output of

In a region of magnetic induction $B = 10^{-2}$ tesla, a circular coil of radius 30 cm and resistance $\pi^2$ ohm is rotated about an axis which is perpendicular to the direction of $B$ and which forms a diameter of the coil. If the coil rotates at 200 rpm the amplitude of the alternating current induced in the coil is