Practice free NEET NEET multiple-choice questions online with instant answers and detailed explanations. No login required.
The inductive reactance ($X_L$) of a pure inductor is directly proportional to:
The example calculates inductive reactance as $X_L = 2\pi \nu L$. This formula clearly shows that inductive reactance is directly proportional to the frequency ($\nu$) of the AC source.
In a purely inductive AC circuit, which of the following statements about the phase relationship between voltage and current is correct?
The text mentions, 'in the case of an inductor, the current lags the voltage by $\pi/2$'. This is equivalent to saying voltage leads current by $\pi/2$.
A pure inductor of 25.0 mH is connected to a 220 V AC source with a frequency of 50 Hz. What is the inductive reactance?
From Example 7.2: $X_L = 2\pi \nu L = 2 \times 3.14 \times 50 \times 25 \times 10^{-3} \Omega = 7.85 \Omega$.
Phasors are used in AC circuits primarily to:
The text states, 'In order to show phase relationship between voltage and current in an ac circuit, we use the notion of phasors. The analysis of an ac circuit is facilitated by the use of a phasor diagram.'
In a purely inductive AC circuit, according to Kirchhoff's loop rule, if the voltage across the source is $v = v_m \sin \omega t$, then the equation for the self-induced EMF is:
From the section 'AC VOLTAGE APPLIED TO AN INDUCTOR', it is stated that 'the self-induced Faraday emf in the inductor' is $L \frac{di}{dt}$. Applying Kirchhoff's loop rule for a pure inductor, $v - L \frac{di}{dt} = 0$, hence $v = L \frac{di}{dt}$.
What happens to the inductive reactance of an inductor if an iron rod is inserted into its interior, assuming negligible resistance?
Example 7.5 states, 'As the iron rod is inserted, the magnetic field inside the coil magnetizes the iron increasing the magnetic field inside it. Hence, the inductance of the coil increases. Consequently, the inductive reactance of the coil increases.'
When an iron rod is inserted into the inductor of a circuit containing a light bulb in series with an AC source (and the inductor), what happens to the glow of the light bulb?
As per Example 7.5: 'As a result, a larger fraction of the applied ac voltage appears across the inductor, leaving less voltage across the bulb. Therefore, the glow of the light bulb decreases.'
A purely inductive circuit is an ideal circuit condition. In reality, inductors usually have:
The text mentions, 'Usually, inductors have appreciable resistance in their windings, but we shall assume that this inductor has negligible resistance' (for the purpose of an ideal purely inductive circuit analysis).
Which of the following conditions is necessary for the production of electromagnetic waves?
According to Maxwell's theory, accelerated charges radiate electromagnetic waves. Neither stationary charges nor charges in uniform motion can be sources of electromagnetic waves. (Context: 'It is an important result of Maxwell’s theory that accelerated charges radiate electromagnetic waves.')
The relationship between the magnitude of the electric field ($E_0$) and the magnetic field ($B_0$) in an electromagnetic wave in vacuum is given by:
From Maxwell's equations, it is seen that the magnitude of the electric and the magnetic fields in an electromagnetic wave are related as $B_0 = (E_0/c)$, which rearranges to $E_0 = B_0c$. (Context: 'It is also seen from Maxwell’s equations that the magnitude of the electric and the magnetic fields in an electromagnetic wave are related as $B_0 = (E_0/c)$ (8.10)')
Ready to ace NEET?
Free access · No credit card required
Yes. You can attempt every NEET question on this page for free without logging in, and check the correct answer with a detailed explanation instantly.
No account is required to attempt questions and view answers. A free account adds bookmarks, personal notes, and progress tracking.
The bank mixes NEET previous year questions (PYQs) with practice questions, each tagged with its exam appearances where applicable.