Match the following lists : Correct Codes are :List - I List - II a. SCR can be turned off by i. it turns off when anode current falls below this value. b. Turn on time of SCR can be reduced by ii. the rectangular pulse of high amplitude and narrow width c. Holding current for an SCR means iii. its anode current interruption d. A forward current can be applied to an SCR after iv. its gate recovery time
a-iii, b-ii, c-i, d-iv
To solve the given problem, let's understand the characteristics and operation of an SCR (Silicon Controlled Rectifier) and its associated terms in power electronics:
- SCR Turn-off Mechanism:
- An SCR can be turned off by interrupting its anode current; this is known as anode current interruption. When the anode current falls below the holding current value, the device turns off.
- Thus, "SCR can be turned off by" should match with "its anode current interruption".
- Turn-on Time Reduction:
- The turn-on time of an SCR can be reduced by applying a gate pulse of high amplitude and narrow width. This is often referred to as a rectangular pulse.
- Thus, "Turn on time of SCR can be reduced by" should match with "the rectangular pulse of high amplitude and narrow width".
- Holding Current Definition:
- The holding current of an SCR refers to the minimum anode current necessary to maintain the SCR in the 'on' state once it has been turned on. Below this current, the SCR will turn off.
- Thus, "Holding current for an SCR means" should match with "it turns off when anode current falls below this value".
- Forward Current Application:
- A forward current can be applied to an SCR after its gate recovery time, ensuring the device is ready to conduct again after being turned off.
- Thus, "A forward current can be applied to an SCR after" should match with "its gate recovery time".
Based on the analysis, the correct matching is:
a-iii (SCR can be turned off by - its anode current interruption),
b-ii (Turn on time of SCR can be reduced by - the rectangular pulse of high amplitude and narrow width),
c-i (Holding current for an SCR means - it turns off when anode current falls below this value),
d-iv (A forward current can be applied to an SCR after - its gate recovery time).
Similar Questions
Which of the following statements are true for SCR ?
(a) UJT is a phase controlling device for SCR rectifier.
(b) The average load voltage of SCR rectifier is greater than average load voltage of ordinary diode rectifier.
(c) Power delivered to the load in SCR rectifier is maximum when SCR firing angle is zero degree.
(d) SCR can control the amount of power fed to the load by switching current OFF and ON upto many thousand times a second.
In two transistor model of an SCR the expression for anode current is given by:
The voltage safety factor (Vf) of a thyristor is given by :
In SCR, the following statements are given :
(a) It acts as a short circuit device.
(b) It acts as an open circuit device.
(c) ON state voltage is approximately 2-5 Volts.
(d) ON state voltage is approximately 50-100 Volts.
Which of the above statements are correct ?
An SCR is turned off by :
For a two transistor model, the value of α1 + α2 is equal to :
Important Questions from Thyristors
_______ is the device which acts like an N-P-N and a P-N-P transistor connected base-to-base and emitter-to-collector.
SCR stands for
A conducting SCR can be opened by reducing __________to zero.
Which of the following statements correctly describes the structure of a Silicon Controlled Rectifier (SCR)?
The thyristors which have a turn-off time less than _________ are called inverter grade thyristors.
