EC
Engineering Classroom
by Himalay Sen

Exams

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Board Questions

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MCQ
821. Which is the main relay for protecting up to 90% of the transmission line-length in the forward direction?
Directional over-current relay
Mho relay
Carrier current protective relay
Impedance relay
ব্যাখ্যা: ব‍্যাখ্যা: The relay is called Mha relay because its character is a straight line, when Plotted on an adminance diagram. It is inherently a directional relay as it desee the fault only in the forward direction
823. কোন বৈশিষ্ট্যের কারণে RAM স্থায়ী স্মৃতি-স্টোরেজ হিসাবে ব্যবহার অনুপযোগী?
Too Slow
Unreliable
Volatility
Too Bulky
ব্যাখ্যা: RAM is a volatility memory. RAM is a part of Computer's main URAM directly accessible by CPU. RAM is used to read and write data into it which is a accessed by CPU randomly.
825. WINDOWS কী?
Antivirus software
Data strong device
Operating system
Programming language
ব্যাখ্যা: Windows হলো Microsoft Corporation নামের একটি বিখ্যাত IT Company দ্বারা তৈরি করা একটি Graphical Interface Operating System. এই Operating System-টিকে ব্যবহার করা হয় বিভিন্ন Device-গুলোকে পরিচালনা ও নিয়ন্ত্রণ করার ক্ষেত্রে। যেমন- Computer, Laptop Smartphone-গুলোতে Microsoft-এর Windows OS ব্যবহার করা হয় সেগুলোকে পরিচালনা ও নিয়ন্ত্রণ করার জন্য।
826. MCB stands for-
Miniature Circuit Breaker
Minimum Capacity Breaker
Molded Circuit Breaker
Maximum Capacity Breaker
ব্যাখ্যা: ব‍্যাখ্যা: MCB of Miniature Circuit Breaker automatically switches off the electrical circuit during an abnormal condinon of the network means in overload condition as well as faulty condition. Now a days we use an MCB in a low voltage electrical network instead of a fuse.
827. Both voltage and current signals are required for-
A plain over-current relay
A differential relay
A directional relay
A biased directional relay
ব্যাখ্যা: ব্যাখ্যা: Directional relay operates when the fault is driving power to flow in particular direction
828. Zero sequence current is used for relaying purpose only in the case of--
Phase over-current relay
Phase impedance relay
Ground over-current relay
Ground impedance relay
ব্যাখ্যা: ব্যাখ্যা: The zero sequence currents are passing through this relay for protection of electrical equipment like generator, transformer ect and the relay is called nank fault relay
830. A fuse wire is made of-
Copper
Tungsten
Nichrome
Lead-tin alloy
ব্যাখ্যা: ব‍্যাখ্যা: A fuse wire is made of lead-tin alloy as they have low melting point as well as they have high resistance.
831. Which one of the following relay has the capability of anticipating the possible major fault in a transformer?
Over current relay
Differential relay
Buchholz relay
Over-fluxing relay
ব্যাখ্যা: ব‍্যাখ্যা: Buchholz relay is the gas detector relay word to prot transformers. It operates when the oil level in the conservator pipe of a transformer is lowered by De accumulation of gas caused by a poor connection or by an incipient break down of insulation
832. সিগন্যালের পারস্পরিক রূপান্তর করে-
রাউটার
হাব
গেটওয়ে
মডেম
ব্যাখ্যা: Modem Modem is short for Modulater- Demodalater. Modem converts analog signals m digital and vice versa, it may be considered an Analog to digital converter or digital to analog converter. Roster : Router connect two or more different networks Hub : A hub is a physical layer networking device which is used to connect multiple devices in a network. Gateway: A gateway is a hardware device.
833. Material used for fuse must have--
Low-melting point & low-specific resistance
High-melting point & low-specific resistance
High-melting point & high-specific resistance
Low-melting point & high-specific resistance
837. How many relays are used to detect inter phase fault of a three-line system?
One
Two
Three
Six
ব্যাখ্যা: ব্যাখ্যা: Three relays are used to detect the inter phase foult of a three-line system. A relay is used when there is a nend to control a circuit with either high voltage or power using a low voltage circuit.
839. একটি কম্পিউটারের Basic components হচ্ছে-
Input/Output devices, RAM and motherboard
Keyboard, monitor, memory and CPU
ক এবং খ উভয়ই
Keyboard, hard disk, processor and monitor
840. Lightning arrester is used for-
Protection of equipment from external lightning
Protection of equipment from short circuits
Protection of equipment from open circuits
All of the above