Find the utilize of an NPN common emitter transistor, bandwidth of an amplifier, and advantage of direct - coupled amplifier.
 
1.	An NPN common emitter transistor, when operated without d-c bias, can be used as a?
A)     d-c restorer
B)     Negative peak clipper
C)     Positive peak clipper
D)     Baseline stabilizer
2.      What is the bandwidth of an amplifier that produces a square wave with a rise time of 2 msec? (Microseconds)
A)     20 kHz
B)     57 kHz
C)     70 kHz
D)     175 kHz
 
3.      An advantage of direct - coupled amplifiers is that they?
A)     Make ideal clippers
B)     Make ideal limiters
C)     Can amplify a signal without inverting it
D)     Can amplify a signal without changing its d-c reference level