MEDIUM
JEE Main
IMPORTANT
Earn 100

Match List-I with List-II.

  List - I   List - II
(a) ωL>1ωC (i) Current is in phase with emf
(b) ωL=1ωC (ii) Current lags behind the applied emf
(c) ωL<1ωC (iii) Maximum current occurs
(d) Resonant frequency (iv) Current leads the emf

Choose the correct answer from the options given below.

66.67% studentsanswered this correctly

Important Questions on Electromagnetic Induction and Alternating Currents

EASY
JEE Main
IMPORTANT
An inductor of 10 mH is connected to a 20 V battery through a resistor of 10  and a switch. After a long time, when maximum current is set up in the circuit, the current is switched off. The current in the circuit after 1 μs is x100 mA. Then x is equal to ______ . (Take e-1=0.37)
MEDIUM
JEE Main
IMPORTANT

A circular conducting coil of radius 1 m is being heated by the change of magnetic field B passing perpendicular to the plane in which the coil is laid. The resistance of the coil is 2 μΩ. The magnetic field is slowly switched off such that its magnitude changes in time as  

B=4π×10-3 T1-t100

The energy dissipated by the coil before the magnetic field is switched off completely is E=______mJ.

HARD
JEE Main
IMPORTANT
A 10 Ω resistance is connected across 220 V-50 Hz AC supply. The time taken by the current to change from its maximum value to the rms value is:
HARD
JEE Main
IMPORTANT

Two circuits are shown in figure (a) and (b). At a frequency of _______ rad s-1 the average power dissipated in one cycle will be the same in both the circuits.

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HARD
JEE Main
IMPORTANT

A 0.07 H inductor and a 12 Ω resistor are connected in series to a 220 V, 50 Hz AC source. The approximate current in the circuit and the phase angle between current and source voltage are respectively.

[Take π as 227

MEDIUM
JEE Main
IMPORTANT

Consider an electrical circuit containing a two way switch S. Initially S is open and then T1 is connected to T2. As the current in R=6 Ω attains a maximum value of steady-state level, T1 is disconnected from T2 and immediately connected to T3. Potential drop across r=3 Ω resistor immediately after T1 is connected to T3 is ______V. (Round off to the Nearest Integer)

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HARD
JEE Main
IMPORTANT
A 100Ω resistance, a 0.1μF capacitor and an inductor are connected in series across a 250 V supply at variable frequency. Calculate the value of inductance of inductor at which resonance will occur. Given that the resonant frequency is 60 Hz.
HARD
JEE Main
IMPORTANT

In the given figure the magnetic flux through the loop increases according to the relation ϕB(t)=10t2+20t, where ϕB is in milliwebers and t is in seconds. The magnitude of current through R=2 Ω resistor at t=5 s is _____ mA.

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