1
GATE EE 2015 Set 2
MCQ (Single Correct Answer)
+2
-0.6
A $$3$$-phase transformer rated for $$33 kV/11kV$$ is connected in delta/star as shown in figure. The current transformers $$\left( {C{T_s}} \right)$$ on low and high voltage sides have a ratio of $$500/5.$$ Find the currents $${i_1}$$ and $${i_2}$$, if the fault current is $$300$$ $$A$$ as shown in figure.
![GATE EE 2015 Set 2 Power System Analysis - Switch Gear and Protection Question 6 English](https://imagex.cdn.examgoal.net/Kz3ytxfWLOuVXlju2/rf2Va4iZH6ubVzDMH0eQCUysPmgrA/vdXKA4mye4figdsyYeO67u/uploadfile.jpg)
2
GATE EE 2014 Set 1
Numerical
+2
-0
The over current relays for the line protection and loads connected at the buses are shown in the figure.
![GATE EE 2014 Set 1 Power System Analysis - Switch Gear and Protection Question 7 English](https://imagex.cdn.examgoal.net/Jmk41hcgWgoROxD05/hg7CrIAGfo8t20mt1rQrn0wtecGgU/YNEwK4Vce1asXM13nhKXhU/uploadfile.jpg)
The relays are IDMT is natural having the characteristic
$${t_{op}} = {{0.14\, \times \,time\,\,multiplier\,\,setting} \over {{{(plug\,\,setting\,\,multiplier)}^{0.02}} - 1}}$$
The maximum and minimum fault current at bus $$B$$ are $$2000A$$ and $$500$$ $$A$$ respectively. Assuming the time multiplier setting and plug setting for relay $${R_B}$$ to be $$0.1$$ and $$5$$ $$A$$ respectively, the operating time of $${R_B}$$ (in seconds) is __________.
Your input ____
3
GATE EE 2010
MCQ (Single Correct Answer)
+2
-0.6
Consider a stator winding of an alternator with an internal high resistance ground fault. The currents under the fault condition are as shown in the figure. The winding is protected using a differential current scheme with current transformers of ratio $$400/5$$ $$A$$ as shown. The current through the operating coil is
![GATE EE 2010 Power System Analysis - Switch Gear and Protection Question 8 English](https://imagex.cdn.examgoal.net/QeIeRO2Si0bmwsOSu/KvbMbTFdJAfp4O8CQHTPDg8AOx3Ab/1saKMMHTNUuTEa4NjC5lfC/uploadfile.jpg)
4
GATE EE 2009
MCQ (Single Correct Answer)
+2
-0.6
Match the items in List-$$I$$ (Type of transmission line) with the items in List-$$II$$ (Type of distance relay preferred) and select the correct answer using the codes below the lists.
List-$$I$$
$$A.$$ Short Line
$$B.$$ Mesium Line
$$C.$$ Long Line
List-$$II$$
$$1.$$ Ohm Relay
$$2.$$ Reactance Relay
$$3.$$ Mho Relay
Questions Asked from Switch Gear and Protection (Marks 2)
Number in Brackets after Paper Indicates No. of Questions
GATE EE Subjects
Electromagnetic Fields
Signals and Systems
Engineering Mathematics
General Aptitude
Power Electronics
Power System Analysis
Analog Electronics
Control Systems
Digital Electronics
Electrical Machines
Electric Circuits