High Voltage Lab 6th Semester

1. Which of the following material is used for overhead line insulators?

• a) Porcelain

• b) Glass

• c) PVC

• d) Steatite

2)Suspension type insulator are subjected to ______________

• a) tensile stress

• b) compressive stress

• c) tensile and compressive stress

• d) depends on its use

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

• a) Suspension insulator

• b) Post insulator

• c) Strain insulator

• d) Shackle insulator

4) Suspension insulator are made up of _____________

• a) glass

• b) porcelain

• c) steatite

• d) epoxy resin

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

• a) Flashover

• b) Mechanical stress

• c) Porosity of materials

• d) Improper vitrification

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

• a) same for all disks

• b) maximum for unit nearest to the line

• c) maximum for unit nearest to the tower

• d) equal to transmission line voltage rating

7) Outdoor switchgear is generally used for voltage beyond

• A. 11 KV

• B. 33 KV

• C. 66 KV

• D. 132 KV

8) For protection of rotating machines against lightning surge .............is used

• A. Lightning arrester

• B. Capacitor

• C. Combination of lightning arrester and a capacitor

• D. Lightning conductor and arrester

9) Group of electrical equipment used to change characteristic of electric power is known as

• (A) Generating station

• (B) Substation

• (C) Transmission system

• (D) All of above

10) A substations used for voltage level change is known as

• (A) Transformer substation

• (B) Power factor correction substation

• (C) Frequency changer substation

• (D) None of above