back to directory
NEET PHYSICSALTERNATING CURRENTHard

Question

For very high frequencies, the effective impedance of the circuit (shown in the figure) will be:

A

4 Ω\Omega

B

6 Ω\Omega

C

1 Ω\Omega

D

3 Ω\Omega

Step-by-Step Solution

In AC circuits, reactance depends on frequency. According to the sources, inductive reactance is XL=ωLX_L = \omega L and capacitive reactance is XC=1/(ωC)X_C = 1/(\omega C) . At very high frequencies (ω\omega \to \infty), XLX_L becomes infinitely large, causing inductors to act as open circuits. Meanwhile, XCX_C approaches zero, causing capacitors to act as short circuits (wires). For the circuit provided in the NEET 2023 (Manipur) exam, these conditions effectively remove the branch containing the inductor and treat the capacitor branch as a purely resistive path. The resulting combination of remaining resistors yields a total effective impedance of 3 Ω\Omega.

Exam Context & Concepts Covered

This question aligns with the NEET PHYSICS syllabus, specifically targeting concepts from ALTERNATING CURRENT. Mastering this topic is crucial for scoring well in the upcoming medical entrance examinations. Solving conceptually related problems will help you understand the nuances of these concepts and improve your problem-solving speed.

PHYSICSALTERNATING CURRENTfrequencieseffectiveimpedancecircuitfigure

More ALTERNATING CURRENT Questions

View all

In an alternating current circuit consisting of elements in series, the current increases on increasing the frequency of the supply. Which of the following elements are likely to constitute the circuit? (a) Only resistor (b) Resistor and an inductor (c) Resistor and a capacitor (d) Only a capacitor

A.(b), (c)
B.(a), (d)
C.(b), (d)
D.(c), (d)
MediumSolve

An AC source given by $V = V_m \sin(\omega t)$ is connected to a pure inductor $L$ in a circuit and $I_m$ is the peak value of the AC current. The instantaneous power supplied to the inductor is:

A.$\frac{V_m I_m}{2} \sin(2\omega t)$
B.$-\frac{V_m I_m}{2} \sin(2\omega t)$
C.$V_m I_m \sin^2(\omega t)$
D.$-V_m I_m \sin^2(\omega t)$
MediumSolve

A transformer having efficiency of 90% is working on 200 V and 3 kW power supply. If the current in the secondary coil is 6A, the voltage across the secondary coil and the current in the primary coil respectively are:

A.300 V, 15 A
B.450 V, 15 A
C.450 V, 13.5 A
D.600 V, 15 A
MediumSolve

A standard filament lamp consumes 100 W when connected to a 200 V AC mains supply. The peak current through the bulb will be:

A.0.707 A
B.1 A
C.1.414 A
D.2 A
EasySolve

The net impedance of the circuit (as shown in the figure) will be:

A.25 $\Omega$
B.$10\sqrt{2} \ \Omega$
C.15 $\Omega$
D.$5\sqrt{5} \ \Omega$
MediumSolve

A 12 V, 60 W lamp is connected to the secondary of a step-down transformer, whose primary is connected to AC mains of 220 V. Assuming the transformer to be ideal, what is the current in the primary winding?

A.0.37 A
B.0.27 A
C.2.7 A
D.3.7 A
EasySolve

The variation of EMF with time for four types of generators is shown in the figures. Which amongst them can be called AC voltage?

A.(a) and (d)
B.(a), (b), (c), and (d)
C.(a) and (b)
D.only (a)
EasySolve

An inductor of inductance L, a capacitor of capacitance C and a resistor of resistance R are connected in series to an AC source of potential difference V volts. The potential difference across L, C and R is 40 V, 10 V and 40 V, respectively. The amplitude of the current flowing through the LCR series circuit is $10\sqrt{2}$ A. The impedance of the circuit will be:

A.4 $\Omega$
B.5 $\Omega$
C.$4\sqrt{2} \ \Omega$
D.$5\sqrt{2} \ \Omega$
MediumSolve

This neet physics practice question is part of the TopperSquare free question bank. TopperSquare offers 15,000+ chapter-wise NEET MCQs across Physics, Chemistry, and Biology with detailed step-by-step explanations, full mock tests, NEET PYQs (2010–2024), and an AI-powered performance analytics dashboard. browse all neet practice questions → · practice physics sets →