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Consider the following statements: 1. In a silicon controlled rectifier (SCR), if the cathode gate is reverse-biased, then the SCR cannot fire at all. 2. The turn-on time of an SCR increases with temperature. 3. After an SCR is turned on, it can be made to turn off again by reverse biasing the gate. 4. Gate recovery time is the minimum time that the anode voltage must be maintained below holding voltage VH to turn off the SCR. Which of these statements are correct?
The effect of over-voltages on SCR are minimized by using.
A 220 1-ϕ, 220 Ω  resistor is connected in series with the gate of an SCR as shown in the given figure. The gate current required to fire the SCR is 7 mA. what is the input voltage (Vin) required to fire the SCR?
A voltage source Vs = Vm sinωt is connected in series with a resistance R and an SCR. At some firing angle delay of α a positive gate pulse is applied to the SCR which turns on the SCR. Considering ideal conditions, at the instant α the voltage at the resistor terminals Vo
In order to prevent overvoltages at light loads, which of the following should be connected to a transmission system?
In an optical fibre, the pulse dispersion effect is minimized by 1. Using a high frequency light source 2. Using plastic cladding 3. Minimizing the core diameter Which of the above statements is/are correct?
A three-phase three pulse type controlled converter is constructed using 3 SCR devices. The circuit is supplying an R load with α < 30°. As such, each SCR device would conduct for
A single-phase voltage controller, using one SCR in anti parallel with a diode, feeds a load R and Vs = 230 V. For a firing angel of 90° for the SCR, the PMMC voltage connected across R would read
In a 3-phase converter circuit, during commutation when one SCR in one phase is turned on, turning of an SCR in another phase results is:
Consider the following statements: SCR can be turned on by 1. Applying anode voltage at a sufficiently fast rate 2. Applying sufficiently large anode voltage 3. decreasing the temperature of SCR 4. Applying sufficiently large gate current Which of the above statements are correct?