Question: An SCR has __________ pn junctions?

• 1. Two
• 2. Three
• 3. Four
• 4. None of the above

Question: An SCR is turned off when ________________?

• 1. Anode current is reduced to zero
• 2. Gate voltage is reduced to zero
• 3. Gate is reverse biased
• 4. None of the above

Question: If gate current is increased, then anode-cathode voltage at which SCR closes_________________?

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

Question: In an SCR circuit, the angle of conduction can be changed by__________________?

• 1. Changing anode voltage
• 2. Changing gate voltage
• 3. Reverse biasing the gate
• 4. None of the above

Question: When SCR is OFF, the current in the circuit is ________________?

• 1. Exactly zero
• 2. Small leakage current
• 3. Large leakage current
• 4. None of the above

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