341. বিশুদ্ধ সেমিকন্ডাক্টর পদার্থে ভ্যালেন্স ইলেকট্রনের সংখ্যা কত ?

২

৩

৪

৮

342. ১ ইলেকট্রন চার্জ = ?

1.6*10’-18 কুলম্ব

1.6*10’-19 কুলম্ব

1.6*10’-27 কুলম্ব

1.6*10’-19 কুলম্ব

343. Permanent magnet is normally made of-

Aluminum

Wrought iron

Cast iron

Alnico alloys

344. A transformer has negative voltage regulation when its load power factor is-

Zero

Unity

Leading

Lagging

345. Dose the transformer draw any current when its secondary is open ?

No

Yes

Take rated current

None

346. How can eddy current loss be minimized ?

By using copper core

By using solid core

By laminating the core

None of above

347. If the power factor of a circuit is unity, its reactive power is-

A maximum

Equal to FR

Zero

A negative quantity

348. Which is the used power factor improvement-

Spring motor

Commutator motor

Synchronous motor

Squirrel Case Motor

349. Active power is equal to-

F Z

VI Sin

VI Cos

None

350. One Cubic water is equal to-

74.6 U.S Gallon

628 pound water

28.375 Line

28.3 Cubic meter

351. Which power factor is more economical for the consumers-

0.85 Lagging

0.95 Lagging

0.10 Leading

0.85 Leading

352. What would be the charge of a uF when connected with 20V supply?

2000 uC

200 uC

300 uC

30 uC

353. Three equal resistors of hundred ohm is connected in series across a source of E.m.f 30V.What would be the power consumed by is resistor?

10 W

30 W

90 W

60 W

354. The unit of resistivity is

Ohms

Ohm-m

Ohm/sqm

None

355. The phenomena of creeping occurs in

Ammeter

Voltmeter

Wattmeter

Watt-hour meter

356. Common declared distribution voltage in Bangladesh for low voltage circuit is –

230 Volt

440 Volt

250 Volt

350 Volt

357. Which distribution system is more reliable?

Ring main system

Tree system

Radial system

All are equally reliable.

358. Burden of current transformer is usually expressed in-

Volts

Amperes

Volt amperes

Kilowatt

359. Bucholz relay used on-

Air cooled transformer.

Oil cooled transformers.

Welding transformers

Furnace transformer.

360. The type of oil which is suitable as transformer oil is-

Animal oil

Cooking oil

Mineral oil

Vegetable oil