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1.0.0
MCQ
1401. A dynamometer wattmeter can be used for-
DC only
AC only
Both DC and AC
Any of the above
1402. In a portable instrument, the controlling torque is provided by--
Spring
Eddy currents
Gravity
All of the above
1403. Direct method is used to measure-
Length
Pressure
Temperature
Voltage
ব্যাখ্যা: Direct method is used to measure length.
1404. The disc of an instrument using eddy current damping should be of-
Conducting and magnetic material
Non-conducting and magnetic material
Conducting and nonmagnetic material
None of the above
ব্যাখ্যা: Eddy current damping uses conducting and nonmagnetic material.
1405. An instrument transformer is used to extend the range of-
Induction instrument
Electrostatic instrument
Moving coil instrument
Any of the above
1406. For measurement of inductance having high value, we should use-
Maxwell's bridge
Maxwell Wien bridge
Hay's bridge
Any of the above
ব্যাখ্যা: The Hay's bridge is used for determining the self- inductance of the circuit. The bridge is the advanced from of maxwell's bridge. The maxwell's bridge is only appropriate for measuring the medium quality factor. For measuring the high quality factor the Hay's bridge is used in the circuit
1407. An oscilloscope indicates-
Peak to peak value of voltage
DC value of voltage
RMS value
Average value
ব্যাখ্যা: The automatic measurement of various parameters of the signal, like its frequency, peak-to-peak voltage, duty cycle and rise time.
1408. Ryall crest voltmeter is used for measurement of--
AC voltage of any form
Low-frequency voltage
High-DC voltage
High-AC voltage
ব্যাখ্যা: High AC voltage measurement used Ryall crest voltmeter,
1409. Ampere is one of the-
Supplementary units
Derived units
Base units
Units used to measure charge
ব্যাখ্যা: Current unit is Ampere. Ampere is SI base unit.
1410. An ohmmeter is an instrument for measuring-
current
resistance
voltage
wattage
1411. Most sensitive galvanometer is-
Elastic galvanometer
Vibration galvanometer
Duddlb galvanometer
Spot ballistic galvanometer
1412. The operating voltage of a Meggar is about-
6V
12V
40V
100V
ব্যাখ্যা: আমাদের দেশে সাধারণতঃ 500V, 1000V, 2000V-এর মেগার পাওয়া যায়। টেস্ট ভোল্টেজ অনুযায়ী মেগার ইনসুলেশন 'টেস্টার' বিভিন্ন প্রকারের হয়ে থাকে। যথা- 100V, 250V, 500V, 1000V, 2500V, 10,000V.
1413. In a moving coil instrument, the deflecting torque is proportional to-
Current
Square of the current
Squareroot of the current
Sine of the measurand
ব্যাখ্যা: একটি ইনস্ট্রুমেন্টের ডিফ্লেকটিং টর্ক (To), যে কারেন্ট (1) পরিমাণ করতে হবে তার সাথে সরাসরি সমানুপাতিক।
1414. 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.
1415. The internal resistance of an ammeter should be-
Very small
High
Medium
Infinity
1416. An ohmmeter is a---
Moving iron instrument
Moving coil instrument
Dynamometer instrument
None of the above
1417. Resistances can be measured with the help of-
Watt-meters
Voltmeters
Ammeters
Ohmmeters and resistance bridges
1418. 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
1419. In a dynamometer 3-phase power factor meter, the planes of the two moving coils are at----
0°
60°
90°
120°
ব্যাখ্যা: ডায়ানামোমিটার টাইপ পাওয়ার ফ্যাক্টর মিটারে দুটি প্রেসার কয়েলের প্ল্যানের মধ্যবর্তী কোণ 90° এবং 3- power factor meter প্রেসার সার্কিটদ্বয়ের মধ্যবর্তী কোণ 120°
1420. In order to achieve high accuracy, the slide wire of a potentiometer should be-
As long as possible
As short as possible
Neither too small nor too large
Very thick