Electrical Engineering (EE) Exam  >  Electrical Engineering (EE) Tests  >  Test: Insulator for Overhead Lines - Electrical Engineering (EE) MCQ

Test: Insulator for Overhead Lines - Electrical Engineering (EE) MCQ


Test Description

10 Questions MCQ Test - Test: Insulator for Overhead Lines

Test: Insulator for Overhead Lines for Electrical Engineering (EE) 2024 is part of Electrical Engineering (EE) preparation. The Test: Insulator for Overhead Lines questions and answers have been prepared according to the Electrical Engineering (EE) exam syllabus.The Test: Insulator for Overhead Lines MCQs are made for Electrical Engineering (EE) 2024 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests for Test: Insulator for Overhead Lines below.
Solutions of Test: Insulator for Overhead Lines questions in English are available as part of our course for Electrical Engineering (EE) & Test: Insulator for Overhead Lines solutions in Hindi for Electrical Engineering (EE) course. Download more important topics, notes, lectures and mock test series for Electrical Engineering (EE) Exam by signing up for free. Attempt Test: Insulator for Overhead Lines | 10 questions in 30 minutes | Mock test for Electrical Engineering (EE) preparation | Free important questions MCQ to study for Electrical Engineering (EE) Exam | Download free PDF with solutions
Test: Insulator for Overhead Lines - Question 1

If a string of suspension insulator has three units, each can withstand a maximum 11 KV and total string can withstand 25.76 KV. What is the string efficiency?

Detailed Solution for Test: Insulator for Overhead Lines - Question 1

 String Efficiency = [( flashover voltage of the string) / (n × flashover voltage of 1 unit)] × 100
Where ‘n’ is number of units in one string
Hence, String Efficiency = [25.76 / (3 × 11)] × 100
= 78%.

Test: Insulator for Overhead Lines - Question 2

Which type of insulator is used where there is dead end of the line or there is a corner or a sharp curve, for high voltage line?

Detailed Solution for Test: Insulator for Overhead Lines - Question 2

Pin type insulators cannot be used in such situations because they cannot take conductor mechanical load intention which often occurs in such situations for low voltage line. Shackle insulator can be used but for higher voltages transmission lines strain insulator consisting of assembly of suspension type insulator are used.

1 Crore+ students have signed up on EduRev. Have you? Download the App
Test: Insulator for Overhead Lines - Question 3

Which of the following insulator is similar to pin type insulator?

Detailed Solution for Test: Insulator for Overhead Lines - Question 3

Post insulators are very similar to pin type insulator, but has a metal base with a metal cap so that more than one unit can be mounted in series. Suspensions train and shackle insulators are completely different from pin type insulator on the basis of construction.

Test: Insulator for Overhead Lines - Question 4

A transmission line consists of 9 discs of suspension insulator in each string. What is the operating voltage of the transmission line?

Detailed Solution for Test: Insulator for Overhead Lines - Question 4

For different voltage it does not need to use different suspension insulator. Srength of insulator can easily be increased just by adding extra disc of suspension insulators. For 130 KV transmission lines 9 or 10 disks are used.

Test: Insulator for Overhead Lines - Question 5

Which of the following is the main field of application of pin type insulator?

Detailed Solution for Test: Insulator for Overhead Lines - Question 5

Pin type insulator become very bulky and cumbersome when designed for higher voltage. Pin insulators beyond 50,000 Volts becomes uneconomical. the modern practice is not to use pin type insulator SBI on 33kv so use of pin insulator is limited to distribution level voltage.

Test: Insulator for Overhead Lines - Question 6

Which of the following material is not used for overhead line insulators?

Detailed Solution for Test: Insulator for Overhead Lines - Question 6

In addition to high insulation resistance and high relative permittivity, overhead line insulators must have high mechanical strength to bear the weight of line insulators, wind stress and ice loading if any. PVC have good insulation resistance but it does not have such mechanical strength so it is not suitable for overhead line insulators.

Test: Insulator for Overhead Lines - Question 7

Voltage distribution across disc of strings of suspension insulator assembly is ______

Detailed Solution for Test: Insulator for Overhead Lines - Question 7

Thee voltage between line conductor and Earth is not distributed uniformly across individual disks. The unit nearest the conductor has the maximum value across it. The figure progressively decreases as the unit nearest the cross on is approach.

Test: Insulator for Overhead Lines - Question 8

What is the most common cause of failure of overhead line insulators?

Detailed Solution for Test: Insulator for Overhead Lines - Question 8

Failure of overhead line insulators due to mechanical stress is rare because defective pieces are separated during routine factory test. Failure due to porosity and improper vitrification is also very low. The most common cause of failure of overhead line insulator is flashover.

Test: Insulator for Overhead Lines - Question 9

Suspension insulator are made up of _____________

Detailed Solution for Test: Insulator for Overhead Lines - Question 9

Suspension insulators consist of a number of porcelain disks flexibly connected in series by metal links in the form of Strings. Glass is used for making pin type insulators.

Test: Insulator for Overhead Lines - Question 10

Suspension type insulator are subjected to ______________

Detailed Solution for Test: Insulator for Overhead Lines - Question 10

Suspension type insulator hangs from the cross arms of the suspending supporting structure. The line conductor is attached to its lower end hence the load of the conductor causes tensile stress on the suspension insulator.

Information about Test: Insulator for Overhead Lines Page
In this test you can find the Exam questions for Test: Insulator for Overhead Lines solved & explained in the simplest way possible. Besides giving Questions and answers for Test: Insulator for Overhead Lines, EduRev gives you an ample number of Online tests for practice

Top Courses for Electrical Engineering (EE)

Download as PDF

Top Courses for Electrical Engineering (EE)