This set of High Voltage Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Measurement of High Impulse Currents”.
1. What is the bandwidth of Hall generators which is used for impulse current measurement?
a) .5MHz
b) 5MHz
c) 50MHz
d) 500MHz
View Answer
Explanation: The bandwidth of Hall generators which is used for impulse current measurement is 50MHz. It can be used for both ac current as well as impulse current measurements.
2. What is the bandwidth of Rogowski coils with active integrator circuits?
a) about .1MHz
b) about 1MHz
c) about 10MHz
d) about 100MHz
View Answer
Explanation: The bandwidth of Rogowski coils with an integrator or electronics circuit is very large (about 100MHz). Rogowski coils are used for impulse current measurements. The main principle of working is based on mutual induction.
3. Magnetic links are arranged on a __________
a) circular wheel
b) spherical structure
c) rectangular section
d) circular wheel or drum
View Answer
Explanation: Magnetic links are arranged on a circular wheel or drum. They are used for impulse current measurements. These can also be used to measure the peak value of impulse current. Their retentivity is high.
4. The Rogowski coils are wound on magnetic former.
a) True
b) False
View Answer
Explanation: Rogowski coils are used for impulse current measurements. The main principle of working is based on mutual induction. These coils are wound on a nonmagnetic former which are toroidal in shape.
5. The number of turns on the Rogowski coil is __________
a) small
b) large
c) intermediate
d) very small or very large
View Answer
Explanation: The number of turns on a Rogowski coil is chosen to be small. Rogowski coils are used for impulse current measurements. The main principle of working is based on mutual induction. These coils are wound on a nonmagnetic former which are toroidal in shape.
6. The magnetic links are high retentivity steel strips.
a) True
b) False
View Answer
Explanation: Magnetic links are arranged on a circular wheel or drum. They are used for impulse current measurements. These can also be used to measure the peak value of impulse current. Their retentivity is high.
7. Which of the following device is used for post arc and plasma current measurements?
a) Magnetic links
b) Rogowski coil
c) Faraday generator
d) Hall generators
View Answer
Explanation: Hall generators are used for post arc and plasma current measurements. The bandwidth of Hall generators which is used for impulse current measurement is 50MHz. It can be used for both ac current as well as impulse current measurements.
8. The angle of rotation of plane of light beam used in the Faraday generator is given by __________
a) α=VBI
b) α=V/BI
c) α=VB/I
d) α=1/VBI
View Answer
Explanation: The angle of rotation of plane of light beam used in the Faraday generator is given by α=VBI. V is a constant of crystal and depends on the wavelength of the light. B is the magnetic flux density and l is the length of the crystal.
9. Faraday ammeter cannot operate for dc current.
a) True
b) False
View Answer
Explanation: Faraday ammeter cannot operate for dc current. This poses as a major disadvantage. The major advantage of this device is that there is no electric connection between the source and the device.
10. __________ are used for measurement high frequency currents.
a) Magnetic links
b) Rogowski coils
c) Current Transformers
d) Hall generators
View Answer
Explanation: Current Transformers are used for measurement high frequency currents. These transformers usually have an air core or a ferrite core. This device has got a wide measuring range.
Sanfoundry Global Education & Learning Series – High Voltage Engineering.
To practice all areas of High Voltage Engineering, here is complete set of Multiple Choice Questions and Answers.
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