1
GATE EE 2014 Set 2
Numerical
+2
-0
The $$SCR$$ in the circuit shown has a latching current of $$40$$ $$mA.$$ A gate pulse of $$50$$ $$\mu s$$ is applied to the $$SCR$$. The maximum value of $$R$$ in $$\Omega$$ to ensure successful firing of the $$SCR$$ is ____________. 2
GATE EE 2013
+2
-0.6
Thyristor $$T$$ in the figure below is initially off and is triggered with a single pulse of width $$10\mu s.$$ It is given that $$L = \left( {{{100} \over \pi }} \right)\mu H$$ and $$C = \left( {{{100} \over \pi }} \right)\mu F.$$ Assuming latching and holding currents of the thyristor are both zero and the initial charge on $$C$$ is zero, $$T$$ conducts for A
$$10\mu s$$
B
$$50$$ $$s$$
C
$$100\mu s$$
D
$$200\mu s$$
3
GATE EE 2009
+2
-0.6
Match the switch arrangements on the top row to be steady $$-$$ state $$V$$ - $$I$$ characteristics on the lower row. The steady state operating points are shown by large black dots.  A
$$A - i,\,\,B - ii,\,\,C - iii,\,\,D - iv$$
B
$$A - ii,\,\,B - iv,\,\,C - i,\,\,D - iii$$
C
$$A - iv,\,\,B - iii,\,\,C - i,\,\,D - ii$$
D
$$A - iv,\,\,B - iii,\,\,C - ii,\,\,D - i$$
4
GATE EE 2007
+2
-0.6
A $$1:1$$ pulse transformer $$(PT)$$ is used to trigger the $$SCR$$ in the adjacent figure. The $$SCR$$ is rated at $$1.5$$ $$kV$$, $$250$$ $$A$$ with $${{\rm I}_L} = 250\,mA,\,\,{{\rm I}_H} = 150\,mA,$$ and $${{\rm I}_{G\max }} = 150mA$$ with $${{\rm I}_L} = 250\,mA,$$ $${{\rm I}_{G\min }} = 100mA.$$ The $$SCR$$ is connected to an inductive load, where $$L$$ $$=150$$ $$mH$$ in series with a small resistance and the supply voltage is $$200$$ $$V$$ $$dc.$$ The forward drops of all transistors/diodes and gate $$-$$ cathode junction during $$ON$$ state are $$1.0V$$

The resistance $$R$$ should be A
$$4.7k\Omega$$
B
$$470k\Omega$$
C
$$47\Omega$$
D
$$4.7\Omega$$
GATE EE Subjects
Electric Circuits
Electromagnetic Fields
Signals and Systems
Electrical Machines
Engineering Mathematics
General Aptitude
Power System Analysis
Electrical and Electronics Measurement
Analog Electronics
Control Systems
Power Electronics
Digital Electronics
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