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1.0.0
MCQ
1. The EMF of Weston standard cell is measured using-
Moving-iron meter
Digital Voltmeter
Moving-coil meter
Potentiometer
2. In a moving iron meter, the deflecting torque is proportional to--
Current through the coil
Square of the current through the coil
Sine of the measurand
Square root of the measurand
3. The two pressure coils of a single phase power factor meter have---
The same dimensions and the same number of turns
The same dimension but different number of turns
The same number of turns but different dimensions
None of the above
4. If the cross-sectional area of a magnetic field increases, but the flux remains—
the same,
the increases
decreases
none
ব্যাখ্যা: We know, B A If area is increases flux density will be decreases because they are inversely proportional to each other.
5. A direct current can be measured by-
AD.C. potentiometer directly
A D.C. potentiometer in conjunction with a standard resistance
A D.C. potentiometer in conjunction with a volt ratio box
None of the above
6. একটি কোষের তড়িচ্চালক শক্তি 1.5V এবং অভ্যন্তরীণ রোধ 2Ω। এর প্রান্তদ্বয় 10Ω রোধের সাথে যুক্ত থাকলে কতটুকু তড়িৎ প্রবাহিত হবে?
0.225 A
0.125 A
40.8 A
8A
7. To measure the flux, devices used are based on-
Voltaic effect
Hall effect
Piezo-clectric effect
Photo-voltaic effect
8. An ohmmeter is an instrument for measuring-
current
resistance
voltage
wattage
9. The multiplier and the meter coil in a voltmeter are in-
Series
Parallel
Series-parallel
None of the above
10. Resistances can be measured with the help of-
Watt-meters
Voltmeters
Ammeters
Ohmmeters and resistance bridges
11. In a portable instrument, the controlling torque is provided by--
Spring
Eddy currents
Gravity
All of the above
12. No eddy current and hysteresis losses occur in-
Electrostatic instruments
PMMC instruments
Moving iron instruments
Electrodynamo meter instruments
13. Wien bridge is useful for measuring-
Very high frequency
Medium frequency
Low frequency
High frequency
14. The absolute measurement of resistance is done by-
Ohm's law method
Bridge method
Rayleigh method
Lorenz method
15. A megger is usually-
Moving iron type instrument
Electro-static type instrument
Hot-wire type instrument
Moving coil type instrument
16. Most sensitive galvanometer is-
Elastic galvanometer
Vibration galvanometer
Duddlb galvanometer
Spot ballistic galvanometer
17. A moving iron ammeter may be compensated for frequency errors by-
A shunt resistance
Shunt capacitance
A series inductance
Series resistance
18. The resistance can be measured most accurately by-
Voltmeter-ammeter method
Bridge method
Multimeter
Megger
19. The spring material used in a spring control device should have the following property---
Should be non-magnetic
Most be of low temperature coefficient
Should have low specific resistance
All of the above
20. The chemical effect of current is used in---
DC ammeter hour meter
DC ammeter
DC energy meter
None of the above