The figure of a generator is given below

1. What do the parts X , A represent in the figure.
2. What is the energy change occurs in such a device.
3. What is the use of part Y in the figure

The figure shows a resister, galvanometer connected to a 6V battery.

1. In what way the instruments got connected in the circuit.
2. In which direction does the galvanometer needle deflects.
3. If the battery is replaced by an AC source, what change may be observed in the deflection of galvanometer needle? Why?

In our country the frequency of AC produced for transmission is 50Hz.

1. What does it mean by frequency of an AC?
2. In one second, how many times the direction of EMF change?

Observe the figures a,b,c given below and answer the questions (Solenoid,Bar magnet and galvanometer)

1. In which solenoid the intensity of current is more?
2. What will be the change in deflection of the galvanometer if the magnet in b &c circuits get into the solenoid.

An armature coil of an AC generator when moved in the magnetic field, induced current is produced.

1. Which is the law that helps to find the direction of current.
2. As per the law what does the fore finger represent?

Whenever change occurs to the magnetic flux connected to a closed circuit, a current is induced.

1. What is this phenomenon known as?
2. Name an instrument that works based on this principle.

Find out the correct statement/statements from those given below.

1. when a magnet is moved close to a solenoid, the magnetic flux linked with the solenoid will decrease.
2. when a magnet is moved close to a solenoid, the magnetic linked with the solenoid will increase.
3. when a magnet is moved close to a solenoid, the magnetic flux linked with the solenoid remains the same

The figure given below shows an instrument that changes sound energy into electrical energy.

1. Name the parts A and B in the figure?
2. In such an instrument, explain how the sound energy is changed into electrical energy?

Some relations regarding transformers are given below. Among these select and write down the one that relates to step up transformers.

1. V_s> V_p
2. I_s < I_p
3.  I_s > I_p
4. V_p>V_s

Correct error in the underlined part of the following statements if any

1. To complete one cycle of an AC, an armature needed to rotate 360⁰.
2. if frequency of an AC is 50Hz, the armature completes 25 cycles per second.
3. In an AC generator, current reverses direction in each half rotation

 A transformer has 10000 turns and 240V , 0.2A in the primary coil. If the current through secondary coil is 0.4A.

1. What kind of transformer is this?
2. Find out the voltage and number of turns in the secondary coil.
3. Calculate maximum power in the secondary coil of this transformer.

Given below is the figure of a transformer

The figures of the two stages of an armature that rotates in a magnetic field is shown below.

Find out the odd one and Justify your answer.                                                                Microphone, loud speaker, Transformer, Generator

By increasing diameter of conductors, transmission loss could be reduced.

1. What are the difficulties that arises if thick wires used as transmission lines.
2. Suggest another method to reduce transmission loss.

Identify the relation in the first pair and complete the following:                                   Electro-magnetic induction: Moving coil microphone                                                   Mutual Induction :..............................

The number of turns in the primary of a transformer is two times greater than that in the secondary, then

1. identify the type of transformer?
2. If 50V is given to the primary, What will be the voltage obtained in the secondary?
3. If the current in its primary coil is 4A What will be the current in the secondary?

Find out the relation and fill in the blanks

Select and write down the correct statements regarding a step down transformer from those given below.

1. current is same in primary and secondary.
2. Power is same in primary and secondary.
3. as compared to the secondary coil current Primary coil current is less.
4. Current in the secondary is less than the current in the primary.

1. which instrument is shown above? What is its working principle?
2. When 100V AC is applied at A ,the current was 2A. Calculate the Voltage and current received at B.

The figure shows copper coils of same thickness and different turns arranged in four circuits. If all the bulbs are of same power answer the following questions analysing each figure.

1. If all the circuits are kept on ,which bulb in the circuit glows with least intensity. Justify your answer.
2. If a soft iron core of the same size is inserted in each of the coils, which among the circuits shows most change in the intensity of light..

Identify the relationship between the terms in the first pair and fill up the second pair accordingly:                                                                                                                Generator  :  Armature                                                                                                  Moving coil microphone   :    ..............

The figure of a DC generator is given below.

1. What is the structural deference of DC generator and AC generator.
2. Compare the energy change taking place in an electric motor and a DC generator.
3. Through the current produced in a DC generator is AC, DC is received in the output. How?

Identify the relation in the first pair and complete the second pair.

The current in the primary of a step up transformer that has no energy loss is........            (More, Less, equal)

First part of a house hold circuit is shown in the figure:

1. Draw the diagram as it is, and label all instruments.
2. Complete the circuits after drawing with the inclusion of two lambs , one fan, one three pin plug for a newly build room.
3. Draw the circuit diagram which includes two lambs , one fan and a three pin plug

Observe the figure and answer the questions given.