Class 11 Electronics Chapter 9 Wire Preparation Methods

Class 11 Electronics Chapter 9 Wire Preparation Methods 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 11 Electronics Chapter 9 Wire Preparation Methods Question Answer and select need one. Class 11 Electronics Chapter 9 Wire Preparation Methods Notes Download PDF. AHSEC Class 11 Elective Electronics Question Answer English Medium.

Class 11 Electronics Chapter 9 Wire Preparation Methods

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 11 Electronics Textual Solutions are part of All Subject Solutions. Here we have given AHSEC Class 11 Electronics Textbook Solutions English Medium for All Chapters, You can practice these here.

Wire Preparation Methods

Chapter: 9

CHECK YOUR PROGRESS

A. Multiple choice questions:

1. Which of the following is used as electrical connector for an electric cable? 

(a) Lug. 

(b) Plastic jacket. 

(c) Clip. 

(d) Tape.

Ans: (a) Lug.

2. Which of the following tools is used for insulation removal in a coaxial cable? 

(a) Cutter. 

(b) Stripper.

(c) Mechanical crimping tool.

(d) Hydraulic crimping tool.

Ans: (b) Stripper.

3. The size of dies varies from ______________ to ______________ diameter connectors.

(a) 25 mm, 300 mm. 

(b) 25 mm, 400 mm. 

(c) 35 mm, 400 mm. 

(d) 15 mm, 400 mm. 

Ans: (c) 35 mm, 400 mm.

4. Which of the following tools is required for crimping of a 70mm cable? 

(a) Mechanical crimping tool. 

(b) Hydraulic crimping tool. 

(c) Both (a) and (c). 

(d) Stripper.

Ans: (b) Hydraulic crimping tool.

5. Which of the following tools require oil for its smooth operation? 

(a) Stripper.

(b) Hydraulic crimping tool. 

(c) Plier.

(d) Cutter.

Ans: (b) Hydraulic crimping tool.

6. Lugs are made of ______________ and ______________. 

(a) Aluminium and silver. 

(b) Silver and copper. 

(c) Copper and zinc. 

(d) Aluminium and copper.

Ans: (d) Aluminium and copper.

7. Which of the following precautions must be taken while refilling oil in a hydraulic crimping tool? 

(a) Use only the specified oil.

(b) Never use old oil.

(c) Oil must be clean and non-contaminated.

(d) All of the above.

Ans: (d) All of the above.

8. Which of the following tools is used for wire bending? 

(a) Plier. 

(b) Screwdriver. 

(c) Stripper. 

(d) Cutter.

Ans: (a) Plier.

9. Which of the following tools is required for making noose (loop) in a wire? 

(a) Round nose plier. 

(b) Cutter. 

(c) Stripper.

(d) Hammer. 

Ans: (a) Round nose plier.

10. Which of the following is not a type of joint? 

(a) Western union joint.

(b) Fixture joint.

(c) Knotted tap joint.

(d) Axial joint.

Ans: (d) Axial joint.

B. Fill in the blanks: 

1. Insulation can be removed from an electric wire by using a _____________. 

Ans: Stripper.

2. Electrical connectors are called _____________. These are used for crimping of electrical cables. 

Ans: Lugs.

3. The oil level in a tank must be checked at regular intervals in _____________. 

Ans: Hydraulic crimping tool.

4. Lugs are made of _________________ and ______________. 

Ans: Aluminium and copper.

5. Non-adjustable stripping tool can be adjusted according to the length of the _____________. 

Ans: Strip.

6. There is a spring in the cable clamp and the cutter can be adjusted according to the thickness of the _____________. 

Ans: Outer sheath.

7. The size of a wire must match the correct __________ of the stripper. 

Ans: Notch.

8. Lugs are punched onto a cable using ___________ tool. 

Ans: Crimping.

9. Clips are used for organising and _____________ of cables. 

Ans: Grouping.

10. Lugs are _____________ connection. 

Ans: Solderless.

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

1. Hook and loop straps must be used to secure the cables. 

Ans: True.

2. Lugs are made of zinc and iron. 

Ans: False.

3. The size of dies varies from 35 to 400mm diameter connectors. 

Ans: True.

4. Hydraulic crimping tools are used to crimp copper and aluminium cable lugs or connectors onto cables.

Ans: True.

5. Crimping tool die is designed for reliable and controllable electrical connection. 

Ans: True.

6. A wire cutter is used for making markings on the wire. 

Ans: False.

7. Non-adjustable stripping tool can be adjusted according to the length of the strip. 

Ans: True.

8. Bends are made gradually while routing electrical cables. Sharp bends in the cable must be avoided. 

Ans: True.

9. Use standard vinyl or PVC tape to wrap over the armour rings. 

Ans: True.

10. Knives cannot be used for stripping of coaxial cable.

Ans: False.

D. Short answer questions:

1. Write down the uses of a screwdriver and crimping tool.

Ans: The uses of a screwdriver and crimping tool are:

Screwdriver:

(i) A screwdriver is a basic tool used in electrical panel installation.

(ii) It is manual or powered and is used for inserting and removing screws.

(ii) It consists of a handle and a shaft.The end tip of the screwdriver is inserted into the screw before turning it to adjust or remove it .

Crimping Tool:

(i) Crimping tools are used for punching connectors onto metallic conductors.

(ii) There are two types of crimping tools: mechanical and hydraulic.

(a) Mechanical crimping tool: Used for crimping wires with diameters ranging from 2.5 to 16mm.

(b) Hydraulic crimping tool: Used for crimping copper or aluminium cable lugs, with cables having diameters ranging from 35 to 1000mm 

2. What are the steps of crimping?

Ans: The steps of the crimping process are as follows:

Step 1: Strip the insulation of the wire.

Step 2: Make the tip of the wire firm by twisting the conductor material to enable better connection for the connector .

Step 3: Place the wire into the connector in such a way that the bare part of the wire touches the bare part of the connector.

Step 4: Enter the wire along with the connector into the crimping tool.

Step 5: Squeeze the tool with force.

Step 6: After completion of the process, check that the wire and the connector are together even after applying force.  If you are able to pull off the connector from the wire, crimping has not been done properly.

3. Write short notes on the following.

(i) Hydraulic crimping tool. 

Ans: Hydraulic crimping tool This tool is used to crimp copper or aluminium cable lugs. Connectors can also be crimped onto the cable for cable connection. Cables having a diameter from 35 to 1000mm can be crimped.

(ii) Die.

Ans: A crimping tool die is designed for reliable and controllable electrical connection. Dies, which can be attached to a hydraulic crimping tool, are available in different sizes.

(iii) Lug.

Ans: Lug (electrical connector) is an enclosure tied to an electric cable. It is used for supporting the connection of a cable. Lug is made of aluminium or copper. It helps tighten the connection. It is a solderless electrical connection. Lugs are punched on to the cable using crimping tools 

4. What steps need to be taken for the care and maintenance of a hydraulic crimping tool?

Ans: Cleaning: Dust, sand, environmental influences like high salt index, in particular, and dirt, in general, are harmful for hydraulic crimping tools. It is important to clean these tools carefully.

5. Name the different type of joints used for cables.

Ans: The  different types of joints used for cables are:

(i) Western union joint: It is a straight joint used for small solid cables. To form a western union joint, the following points have to be considered.

(a) Remove the insulation. 

(b) Bring the two conductor wires to a crossed position, and then, make a long bend or twist in each wire. 

(c) Wrap the end of one of the wires around the straight portion of the other wires, and then do the same for the other wire. Repeat this for about four to five times. 

(d) Press the ends of the wires down close to straight portions of the wires to prevent the ends from intruding through the insulation tape.

(e) Insulate the joint using the tape.

(ii) Fixture joint: It is a type of branch joint, connecting a small diameter wire with a large diameter conductor, such as those used in lighting fixtures.To form a fixture joint, the following points have to be considered. 

(a) Remove the insulation. 

(b) Now, wrap the fixture wire  around the branch wire.

(c) Bend the branch wire over the completed turns. 

(d) Wrap the remaining fixture wire over the bent  branch wire. 

(e) This can be followed by soldering and taping, or simply taping of the joint.

(iii) Knotted tap joint: It is used to connect a branch wire to the main wire. To form a knotted tap joint, the following points have to be considered.

(a) Remove about 1 inch of insulation from the main wire and about 3 inches from the branch wire.

(b) Place the branch wire behind the main wire so that three–fourth of its bare wire extends above the main wire.

(c) Bring a branch wire over the main wire. Then, turn the branch wire in a way that it forms a knot over the main wire. Wrap the branch wire around the main wire. Knots of the branch wire on the main wire should be short and tight. Trim the remaining terminal of the branch wire.

(iv) Joints using wire nut and split bolt:  A wire nut replaces a rattail joint splice. The nut is, usually, housed in a plastic insulating casing. The process to make a joint using a wire nut and split bolt are as follows.

(a) Strip the conductors.

(b) Place the two wires to be joined into the wire nut.

(c) Twist and tighten the nut to form a joint.

(v)  Split bolt connector: A split bolt is used to joint large conductors. This replaces the knotted tap joint and can be used to join three ends or a branch wire with a continuous conductor. The bare wires are placed in the space between the two bolts, after which the nut is tightened to ensure a sound joint.

6. List the steps for cable preparation.

Ans: The steps for cable preparation are as under:

(i) Remove the sheathing and wiring armour.

(ii) Separate the wire armour and bend the wires away from the cable. Place a support ring under the armour at each side of the joint.

(iii) Cut back the cable insulation.

(iv) Remove the insulation from each conductor.   

7. What are the type of hand-operated strippers?

Ans: The types of hand-operated strippers are: 

(i) Adjustable hand stripper: This tool uses V-shaped jaws for cutting the insulation of a wire. It is like a pair of scissors with a little notch to cut the insulation.There is a stop screw that can be adjusted back and forth. 

(ii) automatic stripper: The word automatic denotes the self-adjusting feature of the stripper. In an automatic stripper, there is no need to move the screw manually to adjust the opening of the jaws. The automatic stripper has predefined holes as per the gauge standard of a wire. Wire that has to be stripped has some standard gauge.This wire is inserted in the appropriate hole, having the same gauge value of automatic stripper. 

(iii) Non-adjustable Stripper: This type of stripper can be adjusted based on the length of the wire to be stripped. The jaws are designed to grip the wire insulation and remove it without damaging the conductor.