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A coil has resistance 30 Ω and inductive reactance 20 Ω at 50 Hz frequency. If an AC source of 200 V, 100 Hz, is connected across the coil, the current in the coil will be:
A resistance 'R' draws power 'P' when connected to an AC source. If an inductance is now placed in series with the resistance, such that the impedance of the circuit becomes 'Z', the power drawn will be:
A circuit containing an 80 mH inductor and a 60 µF capacitor in series is connected to a 230 V, 50 Hz supply. The resistance of the circuit is negligible. The current amplitude is:
In an AC circuit, an alternating voltage $\varepsilon = 200\sqrt{2}\sin(100t)$ V is connected to a capacitor of capacity $1 \mu\text{F}$. The RMS value of the current in the circuit is:
In terms of Bohr radius a₀, the radius of the second Bohr orbit of a hydrogen atom is given by
The ionisation energy of hydrogen atom is 13.6 eV, the ionisation energy of helium atom would be:
One end of the string of length $l$ is connected to a particle of mass $m$ and the other end is connected to a small peg on a smooth horizontal table. If the particle moves in a circle with speed $v$, the net force on the particle (directed towards the centre) will be: ($T$ represents the tension in the string)
Newton's second law gives the measure of:
Consider aiming a beam of free electrons towards free protons. When they scatter, an electron and a proton cannot combine to produce a H-atom,
The voltage reading on the voltmeter V in the circuit shown below will be:
The colour code of resistance is given below: The values of resistance and tolerance, respectively are:
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 series R-C circuit is connected to an alternating voltage source. Consider two situations: 1. When the capacitor is air-filled. 2. When the capacitor is mica filled. If the current through the resistor is $I$ and voltage across the capacitor is $V$, then:
The Balmer series for the H-atom can be observed: (a) if we measure the frequencies of light emitted when an excited atom falls to the ground state (b) if we measure the frequencies of light emitted due to transitions between excited states and the first excited state (c) in any transition in a H-atom (d) as a sequence of frequencies with the higher frequencies getting closely packed
In an AC circuit the emf (e) and the current (i) at any instant are given respectively by e = E₀ sin ωt, i = I₀ sin(ωt - ϕ). The average power in the circuit over one cycle of AC is
In an electrical circuit R, L, C, and an AC voltage source are all connected in series. When L is removed from the circuit, the phase difference between the voltage and the current in the circuit is π/3. If instead, C is removed from the circuit, the phase difference is again π/3. The power factor of the circuit is:
Power dissipated in an L-C-R series circuit connected to an AC source of emf ε is
An inductor 20 mH, a capacitor 50 μF, and a resistor 40 Ω are connected in series across a source of emf V = 10 sin 340t. The power loss in the AC circuit is:
An inductor of inductance 2 mH is connected to a 220 V, 50 Hz AC source. Let the inductive reactance in the circuit be $X_1$. If a 220 V DC source replaces the AC source in the circuit, then the inductive reactance in the circuit is $X_2$. $X_1$ and $X_2$, respectively, are:
An inductor $20 \text{ mH}$, a capacitor $50 \mu\text{F}$, and a resistor $40 \, \Omega$ are connected in series across a source of emf $V = 10\sin(340t)$. The power loss in the AC circuit is: