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LMRC(UP METRO) PREVIOUS YEAR QUESTION PAPER AND ANSWERS

#LMRC PREVIOUS YEAR QUESTION PAPER AND ANSWERS 1. The unit of electro-chemical equivalent (ECE) is A. km/C B. g/C C. cm/C D. ml/C                                                               Ans- B 2. A machine which converts mechanical energy into electrical energy is known as ______. A. a transducer B. a converter C. a motor D. a generator                                                               Ans - D 3. What is the resistance of a lamp if 10 V battery reasult in 200 mA current flowing through it ? A. 50 B. 25 C. 48 D. 45                                          ...

SEMI CONDUCTOR DEVICE

 * The transistor operate at low voltage with sufficient amount of current. Hence they are known as current operated devices . * The power handling capacity of a semiconductor is relatively lower than that of valves . * In complementary amplifier circuit — one PNP &one NPN  transistor in series is used * The frequency on which the gain of a transistor is reduced to 70.7 %  of its value at low frequency is called alpha cut off frequency of that transistor. * UJT — uni junction  transistor  ( Voltage control device )       - It has three terminal (emitter , base 1 , base 2 )      -   It has stable negative resistance characteristics       - It is used at low frequency, relaxisation oscillator & timer      - It is also called double base transistor  * SCR — Silicon controlled rectifier ( Unidirectional switch )     - It has 4 Layer , 3 junction , 3 terminals...