ELEX10 – Power Electronics Questions With Complete Solutions

ELEX10 – Power Electronics Questions With Complete
Solutions


The terminals of a UJT are :
A. emitter , base , gate
B. emitter , base , base2
C. anode , anode2 , emitter
D. cathode1 , cathode2 , emitter
B. emitter , basel , base2
To turn ON a UJT , the emitter voltage must :
A. reached the valley voltage
B. reached the peak voltage
C. reached the holding voltage
D. be positive
B. reached the peak voltage
The peak voltage is the sum of :
A. forward diode drop and base1 resistance voltage drop
B. forward diode drop and base2 resistance voltage drop
C. base1 and base2 resistance voltage drop D. VBB
A. forward diode drop and basel resistance voltage drop
The ratio between the RB1 and the sum of RB1 and RB2 in a
UJT is called :
A. turns ratio .
B. peak ratio .
C. valley ratio .
D. stand - off ratio

,D. stand - off ratio
The cut off region of a UJT is :
A. below the Iv
B. below the Ip
C. between Iv and Ip
D. above the Iv
B. below the Ip
The cut off region of a UJT is :
A. below the valley point .
B. below the peak point
C. between peak point and valley point
D. above the valley point
point B. below the peak point
A behavior in electronic devices where the current and voltage
behaves inversely with each other .
A. Ohmic region
B. Ohmic effect
C. Reciprocity resistance
D. negative resistance
D. negative resistance
The negative resistance region of a UJT is :
A. below the valley point
B. below the peak point
C. between peak point and valley point
D. above the valley
C. between peak point and valley point

, The saturation region of a UJT is :
A. below the valley point
B. below the peak point
C. between peak point and valley point
D. above the valley point
C. between peak point and valley point above
It is a type of three - terminal thyristor that is triggered into
conduction when the voltage at the anode exceeds the voltage at
the gate .
A. SCS
B. SCR
C. PUT
D. Triac
C. PUT
The gate of a PUT is biased :
A. positively
B. negatively
C. with a positive pulse
D. with a negative pulse
A. positively
To turn on a PUT :
A. apply a positive pulse at the gate
B. apply a negative pulse at the gate
C. VAK exceeds the VG
D. both " apply a positive pulse at the gate " and " VAK exceeds
the VG "