State Lenz’s law. Illustrate, by giving an example, how this law helps in predicting the direction of the current in a loop in the presence of a changing magnetic flux.
In a given coil of self-inductance of 5 mH, current changes from 4 A to 1 A in 30 ms. Calculate the emf induced in the coil.
In a given coil of self-inductance of 5 mH, current changes from 4 A to 1 A in 30 ms. Calculate the emf induced in the coil.
CBSE OUTSIDE DELHI - SET 2 PATNA 2015
Download our app for free and get started
Lenz’s law applies to closed circuit determining the direction of induced current states. “The induced emf will appear in such a direction that it opposes the change that produced it.”
$| \varepsilon| =\text{L}\frac{\text{di}}{\text{dt}}$
$| \varepsilon| =5\times10^{-3}\times\frac{(4 - 1 )}{30\times10^{-3}}\text{V} = 0.5\text{V}.$
$| \varepsilon| =\text{L}\frac{\text{di}}{\text{dt}}$
$| \varepsilon| =5\times10^{-3}\times\frac{(4 - 1 )}{30\times10^{-3}}\text{V} = 0.5\text{V}.$
Download our appand get started for free
Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*
Similar Questions
- 1View SolutionA 600 pF capacitor is charged by a 200 V supply. It is then disconnected from the supply and is connected to another uncharged 300 pF capacitor. Calculate how much electrostatic energy is lost in the process. What is the source of energy loss?
- 2A resistance R and a capacitor C are connected in series to a source $\text{V}=\text{V}_0\sin\omega\text{t}.$View Solution
Find:- The peak value of the voltage across the (i) resistance and (ii) capacitor.
- The phase difference between the applied voltage and current. Which of them is ahead?
- 3View SolutionWhat is space wave propagation? State the factors which limit its range of propagation. Derive an expression for the maximum line of sight distance between two antennas for space wave propagation.
- 4A source of ac voltage $ v= v_0 \sin\omega t$, is connected across a pure inductor of inductance L. Derive the expressions for the instantaneous current in the circuit. Show that average power dissipated in the circuit is zero.View Solution
- 5View SolutionState the principle of a cyclotron. Show that the time period of revolution of particles in a cyclotron is independent of their speeds. Why is this property necessary for the operation of a cyclotron?
- 6Two capacitors of capacitance $10\mu\text{F}$ and $20 \mu\text{F}$ are connected in series with a 6 V battery. After the capacitors are fully charged, a slab of dielectric constant (K) is inserted between the plates of the two capacitors. How will the following be affected after the slab is introduced:View Solution
- The electric field energy stored in the capacitors.
- The charges on the two capacitors.
- The potential difference between the plates of the capacitors.
- 7View SolutionState Ampere's circuital law. Use this law to find magnetic field due to straight infinite current carrying wire. How are the magnetic field lines different from the electrostatic field lines?
- 8View Solution
- Write three characteristic properties of nuclear force.
- Draw a plot of potential energy of a pair of nucleons as a function of their separation. Write two important conclusions that can be drawn from the graph.
- 9View SolutionObtain the resonant frequency and Q-factor of a series LCR circuit with L = 3.0H, C = 27μF, and R = 7.4Ω. It is desired to improve the sharpness of the resonance of the circuit by reducing its ‘full width at half maximum’ by a factor of 2. Suggest a suitable way.
- 10View SolutionExplain briefly the process of charging a parallel plate capacitor when it is connected across a d.c. battery. A capacitor of capacitance ‘C’ is charged to ‘V’ volts by a battery. After some time the battery is disconnected, and the distance between the plates is doubled. Now a slab of dielectric constant, 1 < k < 2, is introduced to fill the space between the plates. How will the following be affected:
- The electric field between the plates of the capacitor.
- The energy stored in the capacitor.