Power Electronics
An SCR is considered to be a semi controlled device because

 it conducts only during one half cycle of an alternating current wave.
 it can be turned ON only during one half cycle of an AC.
 it can be turned ON but not OFF with a gate pulse.
 it can be turned OFF but not ON with a gate pulse.

ANSWER DOWNLOAD EXAMIANS APP

Power Electronics
Delay time is defined by the interval when

 anode voltage drops from 100 % to 90 % of its actual value.
 gate current increases from 90 % to 100 % of its final value.
 anode current reaches 10 % from forward leakage current.
  all of these.

ANSWER DOWNLOAD EXAMIANS APP