1
AIPMT 2009
+4
-1
Power dissipated in an LCR series circuit connected to an A.C. source of emf $$\varepsilon$$ is
A
$${{{\varepsilon ^2}\sqrt {{R^2} + {{\left( {L\omega - {1 \over {\omega }}} \right)}^2}} } \over R}$$
B
$${{{\varepsilon ^2}\sqrt {{R^2} + {{\left( {L\omega - {1 \over {C\omega }}} \right)}^2}} } \over R}$$
C
$${{{\varepsilon ^2}R} \over {\sqrt {{R^2} + {{\left( {L - {1 \over {C\omega }}} \right)}^2}} }}$$
D
$${{{\varepsilon ^2}R} \over {\left[ {{R^2} + {{\left( {L\omega - {1 \over {C\omega }}} \right)}^2}} \right]}}$$
2
AIPMT 2008
+4
-1
In an a.c. circuit the e.m.f. ($$\varepsilon$$) and the current

(i)  at any instant are given respectively by
$$\varepsilon$$ = E0sin$$\omega$$t,   $$i$$ = $$I$$0sin($$\omega$$t $$-$$ $$\phi$$)

The average power in the circuit over one cycle of a.c. is
A
$${{{E_0}{I_0}} \over 2}\cos \phi$$
B
$${{E_0}{I_0}}$$
C
$${{{E_0}{I_0}} \over 2}$$
D
$${{{E_0}{I_0}} \over 2}\sin \phi$$
3
AIPMT 2007
+4
-1
The primary and secondary coils of a transformer have 50 and 1500 turns respectively. If the magnetic flux $$\phi$$ linked with the primary coil is given by $$\phi$$ = $$\phi$$0 + 4t, where $$\phi$$ is webers, t is time in seconds and $$\phi$$0 is a constant, the output voltage across the secondary coil is
A
120 volt
B
220 volts
C
30 volts
D
90 volts.
4
AIPMT 2007
+4
-1
What is the value of inductance L for which the current is maximum in a series LCR circuit with C = 10 $$\mu$$F and $$\omega$$ = 1000 s$$-$$1 ?
A
1 mH
B
cannot be calculated unless R is known
C
10 mH
D
100 mH
EXAM MAP
Medical
NEET