Question: We can control a.c. power in a load by connecting ______________?

• 1. Two SCRs in series
• 2. Two SCRs in parallel
• 3. Two SCRs in parallel opposition
• 4. None of the above

Question: If firing angle in an SCR circuit is increased, the output _____________?

• 1. Remains the same
• 2. Is increased
• 3. Is decreased
• 4. None of the above

Question: An SCR can exercise control over____________of a.c. supply?

• 1. Positive half-cycles only
• 2. Negative half-cycles only
• 3. Both positive and negative half-cycles
• 4. Positive or negative half-cycles

Question: When SCR starts conducting, then _____________ loses all control?

• 1. Gate
• 2. Cathode
• 3. Anode
• 4. None of the above

Question: The random motion of holes and free electrons due to thermal agitation is called______________?

• 1. Diffusion
• 2. Pressure
• 3. Ionisation
• 4. None of the above

Question: A hole and electron in close proximity would tend to________________?

• 1. Repel each other
• 2. Attract each other
• 3. Have no effect on each other
• 4. None of the above

Question: The battery connections required to forward bias a pn junction are_________________?

• 1. +ve terminal to p and –ve terminal to n
• 2. -ve terminal to p and +ve terminal to n
• 3. -ve terminal to p and –ve terminal to n
• 4. None of the above

Question: In the depletion region of a pn junction, there is a shortage of_________________?

• 1. Acceptor ions
• 2. Holes and electrons
• 3. Donor ions
• 4. None of the above

Question: A pn junction acts as a__________________?

• 1. Controlled switch
• 2. Bidirectional switch
• 3. Unidirectional switch
• 4. None of the above

Question: In an intrinsic semiconductor, the number of free electrons_____________?

• 1. Equals the number of holes
• 2. Is greater than the number of holes
• 3. Is less than the number of holes
• 4. None of the above