Exam Details
| Subject | Electrical Measurements And Instruments | |
| Paper | ||
| Exam / Course | Diploma -VIEP-Electrical Engineering (DELVI)/Advanced Level Certificate Course In Electrical Engineering (ACELVI) | |
| Department | School of Engineering & Technology (SOET) | |
| Organization | indira gandhi national open university | |
| Position | ||
| Exam Date | December, 2015 | |
| City, State | new delhi, |
Question Paper
1. Choose the best option in the following questions:
When the measured value approaches the true value, the reading is
Accurate
Accurate, but not Precise
Precise, but not Accurate
Both Accurate and Precise
A Megger is used for the measurement of
Low valued resistance
Medium valued resistance
High valued resistance, particularly insulation resistance
All of the above
To protect the personnel from high voltage electric shock from an instrument transformer, the following sequence of connections is followed (assuming N1 » N2 in PT and N2» N1 in
In PT, primary winding is connected first, then the secondary.
In PT, secondary winding is connected first, then the primary.
In CT, primary winding is connected first, then the secondary.
In CT, secondary winding is connected first, then the primary.
One of the following connections may spoil the measuring instrument:
An overrated ammeter in series with the load.
An underrated ammeter in series with the load.
A rated voltmeter in series with the load.
A rated voltmeter in parallel to the load.
If the pressure coils in a two-wattmeter method are connected in series, it can measure
Apparent power
Active power
Reactive power
No power
To prevent creeping in an energymeter the following arrangement is made:
Copper shading bands are provided on the central limb.
A permanent magnet is positioned near the edge of the aluminium disc.
A shunt coil is provided on the central limb.
Two diametrically opposite holes are drilled in the aluminium disc.
A Lissajous pattern of straight lines at 60° with x-axis means that the sinusoidal signals are
in phase and of the same magnitude.
60° out of phase and of the same magnitude.
in phase and of the same amplitude.
60° out of phase and of different amplitude.
2. Explain the damping system employed in a measuring instruments. Explain the various types of damping with the help of neat sketches.
Explain the construction and working principle of a maximum demand indicator.
Describe various types of instrument transformers. How do they differ from power transformers?
A moving coil instrument gives full scale reading of 24 rnA, when the potential difference across the terminal is 72 mV. Calculate the resistance to be connected for a full scale deflection corresponding to 120 amp.
Explain the working of a single phase electrodynamometer type power factor meter with the help of a neat sketch.
Describe the construction and working principle of a single phase energy meter.
An energy meter is designed to make 100 revolutions of disc for one unit of energy. Calculate the number of revolutions made by it when connected to a load carrying 40 A at 230 V and 0·4 p.f. for an hour. If it actually makes 360 revolutions, find the percentage error.
6. Discuss the working of a CRO and its various controls with the help of a block diagram.
7. Write short notes on any two of the following:
Phase Sequence Indicator
Analogue Multimeter
Recording Instruments
When the measured value approaches the true value, the reading is
Accurate
Accurate, but not Precise
Precise, but not Accurate
Both Accurate and Precise
A Megger is used for the measurement of
Low valued resistance
Medium valued resistance
High valued resistance, particularly insulation resistance
All of the above
To protect the personnel from high voltage electric shock from an instrument transformer, the following sequence of connections is followed (assuming N1 » N2 in PT and N2» N1 in
In PT, primary winding is connected first, then the secondary.
In PT, secondary winding is connected first, then the primary.
In CT, primary winding is connected first, then the secondary.
In CT, secondary winding is connected first, then the primary.
One of the following connections may spoil the measuring instrument:
An overrated ammeter in series with the load.
An underrated ammeter in series with the load.
A rated voltmeter in series with the load.
A rated voltmeter in parallel to the load.
If the pressure coils in a two-wattmeter method are connected in series, it can measure
Apparent power
Active power
Reactive power
No power
To prevent creeping in an energymeter the following arrangement is made:
Copper shading bands are provided on the central limb.
A permanent magnet is positioned near the edge of the aluminium disc.
A shunt coil is provided on the central limb.
Two diametrically opposite holes are drilled in the aluminium disc.
A Lissajous pattern of straight lines at 60° with x-axis means that the sinusoidal signals are
in phase and of the same magnitude.
60° out of phase and of the same magnitude.
in phase and of the same amplitude.
60° out of phase and of different amplitude.
2. Explain the damping system employed in a measuring instruments. Explain the various types of damping with the help of neat sketches.
Explain the construction and working principle of a maximum demand indicator.
Describe various types of instrument transformers. How do they differ from power transformers?
A moving coil instrument gives full scale reading of 24 rnA, when the potential difference across the terminal is 72 mV. Calculate the resistance to be connected for a full scale deflection corresponding to 120 amp.
Explain the working of a single phase electrodynamometer type power factor meter with the help of a neat sketch.
Describe the construction and working principle of a single phase energy meter.
An energy meter is designed to make 100 revolutions of disc for one unit of energy. Calculate the number of revolutions made by it when connected to a load carrying 40 A at 230 V and 0·4 p.f. for an hour. If it actually makes 360 revolutions, find the percentage error.
6. Discuss the working of a CRO and its various controls with the help of a block diagram.
7. Write short notes on any two of the following:
Phase Sequence Indicator
Analogue Multimeter
Recording Instruments
Other Question Papers
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Subjects
- Basics of Electrical Engineering
- C - Programming
- Computer Applications In P.S.
- Control Systems
- Digital Control System
- Digital Control System Design
- Dynamics System Simulation
- Electrical Circuit Theory
- Electrical Engineering Material
- Electrical Installation and System
- E l e c t r i c a l M a c h i n e T h e o r y I I
- Electrical Machines-I
- Electrical Measurements And Instruments
- Electrical Power Transmission and Distribution
- Energy Audit
- Flexible Ac Transmission System
- Industrial Drives and Controls
- Mechatronics
- Power Generation System
- Power Plant Economics And Centering
- Power System Reliability
- Principles of Computer Architecture
- Special Electrical Machines
- Switchgear And Protection
- Utilization Of Electrical Engineering