Class 12 Electronics Chapter 7 AC Drives and Soft Starters

Class 12 Electronics Chapter 7 AC Drives and Soft Starters 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 7 AC Drives and Soft Starters Question Answer and select need one. Class 12 Electronics Chapter 7 AC Drives and Soft Starters Notes Download PDF. AHSEC Class 12 Elective Electronics Question Answer English Medium.

Class 12 Electronics Chapter 7 AC Drives and Soft Starters

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.

AC Drives and Soft Starters

Chapter: 7

Check Your Progress

A. Multiple choice questions:

1. Which of these is not the role of an electric drive in an electrical system? 

(a) Control speed, position, or torque of different loads. 

(b) Control position. 

(c) Control torque of different loads. 

(d) Circuit breaking.

Ans: (d) Circuit breaking.

2. Which of the following is not the control key on the VFD panel? 

(a) Start reverse run.

(b) Stop/Reset.

(c) Start forward run.

(d) Forward-reverse run.

Ans: (d) Forward-reverse run.

3. Which of the following is not a function key on the VFD panel? 

(a) Enter.

(b) Escape. 

(c) Previous. 

(d) Numlock.

Ans: (d) Numlock.

4. In bridge rectifier the output will be in the form of ___________. 

(a) AC.

(b) DC. 

(c) Pulsating DC. 

(d) Square waveform.

Ans: (c) Pulsating DC.

5. VFD stands for ______________. 

(a) Variety frequency drive. 

(b) Variation fault detection. 

(c) Variation frequency detection.

(d) Variable frequency drive.

Ans: (d) Variable frequency drive.

6. Which of the following components is not in the VFD? 

(a) Power electronic converters. 

(b) Filter.

(c) Central control unit. 

(d) RAM.

Ans: (d) RAM.

7. Bridge full wave rectifier contains ______________.

(a) One diode. 

(b) Two diodes. 

(c) Three diodes. 

(d) Four diodes.

Ans: (d) Four diodes.

8. The role of a capacitor filter in the rectifier is to ________. 

(a) Convert AC to DC.

(b) Remove the noise. 

(c) Remove the DC components in the signal. 

(d) Smoothen the pulsating DC into pure DC.

Ans: (d) Smoothen the pulsating DC into pure DC.

9. Which of the following is not the control scheme of the VFD? 

(a) Scalar control.

(b) Vector control.

(c) Direct torque control. 

(d) Indirect torque control.

Ans: (d) Indirect torque control.

10. Which of the following is not the symbolic representation of LED light? 

(a) Trip. 

(b) Power. 

(c) Run. 

(d) Stop.

Ans: (d) Stop.

B. Fill in the blanks:

1. When an additional wire is connected across the middle of the secondary winding of a transformer, it is known as a ______________. 

Ans: Tapped.

2. The output of a centre tapped full wave rectifier is ______________. 

Ans: Pulsating DC.

3. Filter is made up of ______________ and ______________. 

Ans: Capacitor, resistor.

4. In VFD central controller, ______________ are used to control the operation. 

Ans: Microcontroller or microprocessor. 

5. The schemes of VFD control are ___________, ___________ and ____________.

Ans: Scalar, vector, direct torque.

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

1. By using AC drives, one can change the rotating speed of the motor.

Ans: True.

2. Power modulator converts energy according to the requirement of the motor. 

Ans: True.

3. Centre tapped transformer is used in full wave rectifier. 

Ans: True.

4. Rectifier converts AC power into DC power with negligible ripples. 

Ans: True.

5. In filter, charging time of the capacitor is less compared to the discharging time of the capacitor.

Ans: False.