Class 12 Electronics Chapter 8 Electrical Machines

Class 12 Electronics Chapter 8 Electrical Machines Solutions English Medium As Per AHSEC New Syllabus to each chapter is provided in the list so that you can easily browse through different chapters Class 12 Electronics Chapter 8 Electrical Machines Question Answer and select need one. Class 12 Electronics Chapter 8 Electrical Machines Notes Download PDF. AHSEC Class 12 Elective Electronics Question Answer English Medium.

Class 12 Electronics Chapter 8 Electrical Machines

Also, you can read the NCERT book online in these sections Solutions by Expert Teachers as per Central Board of Secondary Education (CBSE) Book guidelines. AHSEC Class 12 Elective Electronics Textual Solutions are part of All Subject Solutions. Here we have given AHSEC Class 12 Electronics Textbook Solutions English Medium for All Chapters, You can practice these here.

Electrical Machines

Chapter: 8

Check Your Progress

A. Multiple choice questions:

1. The electrical device that converts mechanical energy into electrical energy is ______________. 

(a) Motor. 

(b) Generator. 

(c) Starter. 

(d) Transformer.

Ans: (b) Generator.

2. The rotating part of a motor is ______________. 

(a) Starter.

(b) Carbon brush. 

(c) Armature. 

(d) Stator.

Ans: (c) Armature.

3. The slip ring is used in ______________. 

(a) AC machines. 

(b) DC machines. 

(c) Transformer. 

(d) Stator.

Ans: (a) AC machines.

4. The electrical device that converts electrical energy into mechanical energy is ______________. 

(a) Motor. 

(b) Generator. 

(c) Starter. 

(d) Transformer.

Ans: (a) Motor.

5. In which type of motor is the rotating speed of rotor less than the rotating speed of magnetic field? 

(a) Synchronous motor.

(b) Asynchronous motor. 

(c) DC motor.

(d) Stepper motor.

Ans: (b) Asynchronous motor. 

6. Squirrel cage motor is a type of ______________. 

(a) Synchronous motor.

(b) Asynchronous motor.

(c) DC motor. 

(d) Stepper motor.

Ans: (b) Asynchronous motor.

7. Which of the following motors overcome the drawback  of a squirrel cage motor? 

(a) Stepper motor.

(b) DC motor.

(c) Slip ring motor. 

(d) Series motor.

Ans: (c) Slip ring motor.

8. Which of the following device is used for safe starting of  the induction motor?  

(a) Starter.

(b) Relay. 

(c) Circuit breaker. 

(d) Ground fault detector.

Ans: (c) Circuit breaker. 

9. Which of the following is a component of direct on line starter? 

(a) Relay. 

(b) Contactor. 

(c) Input supply. 

(d) Energy meter.

Ans: (a) Relay.

10. Which of the following is used to connect the wire winding of a motor into star and delta form? 

(a) Thread.

(b) Copper wire. 

(c) Rubber. 

(d) Metal strip.

Ans: (b) Copper wire.

B. Fill in the blanks: 

1. A generator transforms ______________ into ______________. 

Ans: Mechanical energy, electrical energy.

2. Fleming’s ______________ rule is used for electric motor. 

Ans: Left.

3. Fleming’s ______________ rule is used for generator. 

Ans: Right.

4. Electromagnet is an ______________ magnet. 

Ans: Artificial.

5. AC generator is also known as ______________. 

Ans: Alternator.

6. DOL is used to safely start the ______________ motor.

Ans: Induction.

C. State whether the following statements are True or False:

1. Electromotive force is an electrical force, which is exerted on the electrons. This force is responsible for the movement of electrons. 

Ans: True.

2. In an AC generator, current is collected by using a slip ring. While in a DC generator, current is collected by a split ring.

Ans: True.

3. Armature is the rotating part of a motor or generator. 

Ans: True.

4. Brush is the stationary or fixed part of a generator. 

Ans: False.

5. An electric motor is a device that converts electrical energy into mechanical energy.

Ans: True.

6. This rotating force is called torque. 

Ans: True.

7. In synchronous motor the rotating speed of the rotor is the same as the rotating speed of the magnetic field. 

Ans: True.

8. As per Lorentz law, if a current carrying conductor is placed in a magnetic field it will experience a force. 

Ans: False.

9. In slip ring, motor inductor coils are connected in series with the inductive effect of the rotor winding.

Ans: True.