AIIMS Physics Electromagnetic Induction Class 12 Questions

In a LCR oscillatory circuit find the energy stored in inductor at resonance. If voltage of source is 10 V and resistance is 10 Ω and inductance=1 H.

In a LCR oscillatory circuit find the energy stored in inductor at resonance. If voltage of source is 10 V and resistance is 10Ω and inductance = 1H.

For a toroid N = 500, radius = 40 cm, and area of cross section = 10 cm². Find inductance

If maximum energy is stored in capacitor at t = 0 then find the time after which current in the circuit will be maximum.(Circuit parameters: $L = 25 \text{ mH}$, $C = 10 \text{ }\mu\text{F}$)

Consider the following expression. V₂/V₁ = N₂/N₁ Substitute the values as, V₂/120 = 1/50 V₂ = 12/5 Let transformer is ideal. P_in = P_out Therefore, P_out = V₂²/R₂ Substitute the values as, P_out = (12/5)²/10 = 5.76 W

A transformer consists of 500 turn in primary coil and 10 turns in secondary coil with the load of 10 Ω. Find out current in the primary coil when the voltage across secondary coil is 50 V.

A transformer consists of 500 turn in primary coil and 10 turns in secondary coil with the load of 10 Ω. Find out current in the primary coil when the voltage across secondary coil is 50 V.

For an ideal transformer power input is equal to power output. P_{in} = P_{out} E_p I_p = \frac{V_s^2}{R_s} 1000 \times 50 = \frac{220^2}{R_s} R_s = 0.968 \Omega \approx 1 \Omega

Assertion: A metallic surface is moved in and out in magnetic field then emf is induced in it. Reason: Eddy current will be produced in a metallic surface moving in and out of magnetic field.

Assertion : A metallic surface is moved in and out in magnetic field then emf is induced in it. Reason : Eddy current will be produced in a metallic surface moving in and out of magnetic field.

A wire of length 1 m is perpendicular to x-y plane. It is moved with velocity \( \vec{v} = (3\hat{i} + 3\hat{j} + 2\hat{k}) \) m/s through a region of uniform

Assertion: An induced emf appears in any coil in which the current is constant. Reason: Self induction phenomenon does not obey Faraday’s law of induction.

The self inductance of a coil having 500 turns is 50 mH. The magnetic flux through the cross-sectional area of the coil while current through it is 8 mA is found to be

While keeping area of cross-section of a solenoid same, the number of turns and length of solenoid one both doubled. The self inductance of the coil will be

The phase difference between the flux linked with a coil rotating in a uniform magnetic field and induced emf produced in it is

A condensor of 250μF is connected in parallel to a cell of inductance 0.16 mH, while its effective resistance is while its. Determine the resonant frequency

The voltage, V = V₀ / (T/4) t. V = 4V₀/T t

Assertion (A) The bar magnet falling vertically along the axis of the horizontal coil will be having acceleration less than g. Reason (R) Clockwise current induced in the coil.

Assertion: An emf can be induced by moving a conductor in a magnetic field. Reason: An emf can be induced by changing the magnetic field.

Mutual inductance is the phenomenon according to which an opposing e.m.f. produce flux in a coil as a result of change in current or magnetic flux linked with a neighboring coil. But when two coils are inductively coupled, in addition to induced e.m.f. produced due to mutual induction, also induced e.m.f. is produced in each of the two coils due to self-induction.

The self inductance of a coil having 500 turns is $50\text{ mH}$. The magnetic flux through the cross-sectional area of the coil while current through it is $8\text{ mA}$ is found to be

While keeping area of cross-section of a solenoid same, the number of turns and length of solenoid one both doubled. The self inductance of the coil will be

The phase difference between the flux linked with a coil rotating in a uniform magnetic field and induced emf produce in it is

A wire having mass $m$ and length $l$ can freely slide on a pair or parallel smooth horizontal rails placed in vertical magnetic field $B$. The rails are connected by a capacitor of capacitance $C$. The electric resistance of the rails and the wire is zero. If a constant force $F$ acts on the wire as shown in the figure. Then, the acceleration of the wire can be given as

Assertion (A) The bar magnet falling vertically along the axis of the horizontal coil will be having acceleration less than g. Reason (R) Clockwise current induced in the coil.

Mutual inductance M between two concentric coils of radii 1 m and 2 m is

Lenz law is consistent with conservation of

A circular coil with a cross-sectional area of 4 cm² has 10 turns. It is placed at the center of a long solenoid that has 15 turns/cm and a cross-sectional area of 10 cm², as shown in the figure. The axis of the coil coincides with the axis of the solenoid. What is their mutual inductance?

The core of any transformer is laminated so as to

With the decrease of current in the primary coil from 2 amperes to zero value in 0.01s the emf generated in the secondary coil is 1000 volts. The mutual inductance of the two coils is

A metallic ring is dropped down, keeping its plane perpendicular to a constant and horizontal magnetic field. The ring enters the region of magnetic field at t = 0 and completely emerges out at t = T sec. The current in the ring varies as

A conducting ring of radius 1 meter is placed in an uniform magnetic field B of 0.01 tesla oscillating with frequency 100 Hz with its plane at right angle to B. What will be the induced electric field?

A magnet is made to oscillate with a particular frequency, passing through a coil as shown in figure. The time variation of the magnitude of e.m.f. generated across the coil during one cycle is

In an ideal parallel LC circuit, the capacitor is charged by connecting it to a d.c. source which is then disconnected. The current in the circuit

A capacitor of capacitance 2 μF is connected in the tank circuit of an oscillator oscillating with a frequency of 1 kHz. If the current flowing in the circuit is 2 mA, the voltage across the capacitor will be

A rectangular loop carrying a current i₁ is situated near a long straight wire carrying a steady current i₂. The wire is parallel to one of the sides of the loop and is in the plane of the loop as shown in the figure. Then the current loop will

The magnetic needle of a tangent galvanometer is deflected at an angle 30° due to a magnet. The horizontal component of earth's magnetic field 0.34 × 10⁻⁴ T is along the plane of the coil. The magnetic intensity is

Assertion : We use a thick wire in the secondary of a step down transformer to reduce the production heat. Reason : When the plane of the armature is parallel to the line of force of magnetic field, the magnitude of induced e.m.f. is maximum.

Assertion : Faraday's laws are consequences of conservation of energy. Reason : In a purely resistive A.C. circuit, the current lags behind the e.m.f. in phase.

At a place earth's magnetic field, 5 × 10⁻⁵ Wb/m² is acting perpendicular to a coil of radius R = 5 cm. If μ₀/4π = 10⁻⁷, then how much current is induced in circular loop?

If electron is moving from A to B in wire AB, then current induced in the coil is

A small piece of metal wire is dragged across the gap between the pole pieces of a magnet in 0.4 sec. If magnetic flux between the pole pieces is known to be 8 × 10⁻⁴ Wb, then induced emf in the wire, is

Turn ratio in a step-up transformer is 1 : 2. If a Leclanché cell of 1.5 V is connected across the input, what is the voltage across the output?

Eddy currents are produced when

Which of the following statements is true?

The self-induced e.m.f. in closing a d.c. current circuit is e₁, in breaking it is e₂ and the e.m.f. of the source is e₀, then