In a UJT, the emitter terminal is:

This question was previously asked in
ALP CBT 2 Electronic Mechanic Previous Paper: Held on 21 Jan 2019 Shift 1
View all RRB ALP Papers >
  1. Always of the N-Type
  2. P-type for an N bar
  3. Always of the P-Type
  4. of the N-Type for a P bar

Answer (Detailed Solution Below)

Option 3 : Always of the P-Type
Free
General Science for All Railway Exams Mock Test
2.1 Lakh Users
20 Questions 20 Marks 15 Mins

Detailed Solution

Download Solution PDF

The UJT is a three-terminal, semiconductor device which exhibits negative resistance and switching characteristics for use as a relaxation oscillator in phase control applications.

 

F1 R.K. Nita 23.10.2019 D 6

 

  • We observe that the emitter terminal is p-type.
  • The structure of a UJT is quite similar to that of an N-channel JFET.
  • In a unijunction transistor, the emitter is heavily doped while the N-region is lightly doped, so the resistance between the base terminals is relatively high, typically 4 to 10 kilo Ohm when the emitter is open.

 

26 June 1

The basic differences between the UJT and the BJT are as follows:

UJT

BJT

Only one junction is present in UJT.

It consists of two Junctions. It is a two junction transistor.

The conduction in this transistor is based on the flow of the majority of the carriers through it.

The conduction in this transistor is completely based on the flow of both majority as well as the minority carriers through it.

It can be used as the voltage control device.

It can be categorized as the current control device.

UJT cannot be preferred for amplification.

BJT can be used as amplifiers.

Latest RRB ALP Updates

Last updated on Jun 11, 2025

-> The RRB NTPC Admit Card 2025 has been released on 1st June 2025 on the official website.

-> The UPSC Prelims Result 2025 and UPSC IFS Result 2025 has been released @upsc.gov.in

-> Railway Recruitment Board activated the RRB ALP application form 2025 correction link, candidates can make the correction in the application form till 31st May 2025. 

-> The Railway Recruitment Board (RRB) has released the official RRB ALP Notification 2025 to fill 9,970 Assistant Loco Pilot posts.

-> The Railway Recruitment Board (RRB) has released the official RRB ALP Notification 2025 to fill 9,970 Assistant Loco Pilot posts.

-> The official RRB ALP Recruitment 2025 provides an overview of the vacancy, exam date, selection process, eligibility criteria and many more.

->The candidates must have passed 10th with ITI or Diploma to be eligible for this post. 

->The RRB Assistant Loco Pilot selection process comprises CBT I, CBT II, Computer Based Aptitude Test (CBAT), Document Verification, and Medical Examination.

-> This year, lakhs of aspiring candidates will take part in the recruitment process for this opportunity in Indian Railways. 

-> Serious aspirants should prepare for the exam with RRB ALP Previous Year Papers.

-> Attempt RRB ALP GK & Reasoning Free Mock Tests and RRB ALP Current Affairs Free Mock Tests here

Get Free Access Now
Hot Links: teen patti chart teen patti gold download teen patti circle teen patti gold new version 2024 real cash teen patti