1
GATE EE 1999
+2
-0.6
A fixed capacitor of reactance –$$j0.02$$ $$\Omega$$ is connected in parallel across a series combination of a fixed inductor of reactance $$j0.01$$ $$\Omega$$ and a variable resistance $$R.$$ As $$R$$ is varied from zero to infinity, the locus diagram of the admittance of this $$L-C-R$$ circuit will be
A
a semi $$-$$ circle of diameter $$j$$ $$100$$ and center at zero.
B
a semi-circle of diameter $$j$$ $$50$$ and center at zero
C
a straight line inclined at an angle
D
a straight line parallel to the $$x$$ $$-$$ axis.
2
GATE EE 1999
+2
-0.6
The voltage phasor of a circuit is $$10\angle {15^0}\,V$$ and the current phasor is $$2\,\,\angle - {45^0}A.$$ The active and the reactive powers in the circuit are
A
$$10$$ $$W$$ and $$17.32$$ $$VAR.$$
B
$$5$$ $$W$$ and $$8.66$$ $$VAR$$.
C
$$20$$ $$W$$ and $$60$$ $$VAR.$$
D
$$20\,\,\sqrt 2 \,\,W$$ and $$10\sqrt 2 \,\,VAR.$$
3
GATE EE 1997
Fill in the Blanks
+2
-0
Two identical coils of negligible resistance when connected in series across a $$200V,$$ $$50$$ $$Hz$$ source draws, a current of $$10$$ $$A.$$ When the terminals of one of the coils are reversed, then current drawn is $$8$$ $$A.$$ The coefficient of coupling between the two coils is
4
GATE EE 1996
+2
-0.6
A coil (which can be modeled as a series $$RL$$ circuit) has been designed for high $$-$$ $$Q$$ performance at a rated voltage and a specified frequency. If the frequency of operation is doubled, and the coil is operated at the same rated voltage, then the $$Q$$$$-$$factor and the active power $$P$$ consumed by the coil will be affected as follows
A
$$P$$ is doubled, $$Q$$ is halved
B
$$P$$ is halved, $$Q$$ is doubled
C
$$P$$ remains constant, $$Q$$ is doubled
D
$$P$$ decreased $$4$$ times, $$Q$$ is doubled
EXAM MAP
Medical
NEET