JEE Main 2021 (Online) 20th July Morning Shift | Alternating Current and Electromagnetic Induction Question 108 | Physics

JEE Main 2021 (Online) 20th July Morning Shift

MCQ (Single Correct Answer)

-1

AC voltage V(t) = 20 sin$$\omega$$t of frequency 50 Hz is applied to a parallel plate capacitor. The separation between the plates is 2 mm and the area is 1 m². The amplitude of the oscillating displacement current for the applied AC voltage is _________. [Take $$\varepsilon $$₀ = 8.85 $$\times$$ 10^$$-$$12 F/m]

55.58 $$\mu$$A

21.14 $$\mu$$A

27.79 $$\mu$$A

83.37 $$\mu$$A

JEE Main 2021 (Online) 18th March Evening Shift

MCQ (Single Correct Answer)

-1

In a series LCR circuit, the inductive reactance (X_L) is 10$$\Omega$$ and the capacitive reactance (X_C) is 4$$\Omega$$. The resistance (R) in the circuit is 6$$\Omega$$. The power factor of the circuit is :

$${1 \over 2}$$

$${{\sqrt 3 } \over 2}$$

$${1 \over {\sqrt 2 }}$$

$${1 \over {2\sqrt 2 }}$$

JEE Main 2021 (Online) 18th March Evening Shift

MCQ (Single Correct Answer)

-1

The time taken for the magnetic energy to reach 25% of its maximum value, when a solenoid of resistance R, inductance L is connected to a battery, is :

infinite

$${L \over R}$$ ln10

$${L \over R}$$ ln2

$${L \over R}$$ ln5

JEE Main 2021 (Online) 18th March Morning Shift

MCQ (Single Correct Answer)

-1

In a series LCR resonance circuit, if we change the resistance only, from a lower to higher value :

The bandwidth of resonance circuit will increase.

The resonance frequency will increase.

The quality factor will increase.

The quality factor and the resonance frequency will remain constant.