When a magnet is pushed inside a short-circuited coil of wire. When a magnet is pushed inside a short-circuited wire coil, into the short-circuited coil for the first time quickly

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I 1 >I 2

In a magnetic field with induction INF

Emr

is the same along all trajectories

In Ampere's experiment the following was observed

interaction of two parallel conductors with current

In Oersted's experiment the following was observed:

rotation of a magnetic needle near a conductor when current is passed through it

In the circuit shown in the figure, the rheostat slider is moved up. At the same time, the readings

ammeter increased, voltmeter decreased

In a cyclotron, when the speed of a charged particle increases by a factor of 2, its period of revolution (Consider the non-relativistic case ( vc))

Will not change

The electric field intensity vector at point O, created by two charges of the same name, has the direction

The electric field strength vector at the surface of a current-carrying conductor is correctly depicted in the figure

The current-voltage characteristic of a vacuum diode corresponds to the graph

The graph is more consistent with the current-voltage characteristic of a gas discharge

The volt-ampere characteristic of an incandescent lamp filament corresponds to the graph

The expression for the Ampere force modulus corresponds to the formula

F=IBL sin

The expression for the Lorentz force modulus corresponds to the formula

F=qvB sin

The expression for the current strength in a conductor corresponds to the formula

High voltage required for rank(s)

spark

The graph of the dependence of conductor resistance on temperature corresponds to the graph

Two identical sources with EMF are each connected in parallel. Voltmeter readings connected to points 1 and 2

Two resistors having resistance R 1 =3 Ohm and R 2 = 6 Ohm, connected in series direct current. Compare works A electric current on these resistors for the same time

A 2 = 2A 1

The unit of inductance is called

The unit of magnetic flux is called

The unit of magnetic induction is called

The unit of emf is called

From the following statements: 1) the magnetic field is generated by moving charges and an alternating electric field (displacement current); 2) electric field with closed power lines(vortex field) is generated by an alternating magnetic field; 3) power lines magnetic field always closed (this means that it has no sources - magnetic charges similar to electric ones); 4) an electric field with open lines of force (potential field) is generated by electric charges - the sources of this field - the second corresponds to Maxwell’s equation

From the following statements: 1) the magnetic field is generated by moving charges and an alternating electric field (displacement current); 2) an electric field with closed lines of force (vortex field) is generated by an alternating magnetic field; 3) the magnetic field lines are always closed (this means that it has no sources - magnetic charges similar to electric ones); 4) an electric field with open lines of force (potential field) is generated by electric charges - the sources of this field - the first corresponds to Maxwell’s equation

A drop having positive charge+e, lost one electron when illuminated. The charge of the drop became

The wire frame is in a uniform magnetic field. An electric current occurs in it when: 1) the frame is moved along the magnetic field induction lines; 2) the frame is moved across the magnetic field induction lines; 3) the frame is rotated around one of its sides

The wire frame is pushed into a uniform magnetic field (as shown in the figure) In this case, the induced current

directed I - clockwise, II - equal to zero, III - directed counterclockwise

Physical quantity, determined by the work done by the total field of electrostatic (Coulomb) and external forces when moving a single positive charge in a given section of the circuit, is called

voltage

A short-circuited coil is pushed permanent magnet: once quickly, twice slowly Compare the values of the induction current arising in this case

I 1 >I 2

In a magnetic field with induction IN= 4 T the electron moves at a speed of 10 7 m/s, directed perpendicular to the magnetic field induction lines. Force module F, acting on the electron from the magnetic field, is equal to

In a homogeneous electric field tension E= 2 10 3 V/m a charged particle (q = 10 -5 C) with a mass of m= 1 g. When covering a distance r= 10 cm the particle will gain speed

In a uniform electric field, a positive charge moves from point 1 to point 2 along different trajectories. Work of electric field forces

is the same along all trajectories

When a magnet is pushed inside a short-circuited wire coil, an induced current is generated in the coil. Choose the correct statement.
A. The lines of magnetic induction of a magnet's field enter its north pole.

B. The magnet and coil repel each other.

B. Inside the coil, the magnetic field of the induced current is directed upward.

D. The induction current is directed counterclockwise in the coil (when viewed from above).

Physics solver L.A. Kirik Independent and test work

1. The figure shows the magnetic lines of a straight conductor carrying current. Choose the correct statement.
A. The direction of the magnetic line at a given point is taken to be the direction that indicates South Pole magnetic needle placed at this point.
B. To find the direction of magnetic lines, you can use the rule right hand.
B. Magnetic lines are closed only near a straight conductor carrying current.
D. The direction of magnetic lines does not depend on the direction of the current in the conductor.

2. When a short-circuited wire coil is placed on a stationary magnet, an induced current is generated in the coil. Choose the correct statement.

A. The number of magnetic lines piercing the coil does not change in this experiment.
B. The direction of the induction current does not depend on whether the coil is placed on the north or south pole of the magnet.
B. The phenomenon of electromagnetic induction is associated with the occurrence of current in a circuit under the influence of a changing magnetic field.
D. If you remove the coil from the magnet, the direction of the induction current in the coil will not change.

3. A ring made of copper wire is quickly rotated between the poles of a strong electromagnet. At the same time, the ring heats up. Explain why this happens.

When a closed loop of a conductor rotates in a constant magnetic field, the magnetic flux through this loop will change. When the magnetic flux changes according to Faraday's law, an induced emf will occur. Since the circuit is closed, an induction current will flow in it, which will have a thermal effect.

4. What work was done in the conductor electricity, if the charge passed through the circuit is 1.5 C, and the voltage at the ends of this conductor is 6 V?

5. An electric boiler with a spiral resistance of 160 Ohms is placed in a vessel containing 0.5 kg of water at 20 °C and connected to a network with a voltage of 220 V. After 20 minutes, the boiler was turned off. How much water boiled away if the coil efficiency was 80%?

To observe the phenomenon of electromagnetic induction, an electrical circuit is assembled, which includes a moving wire coil connected to an ammeter and a stationary magnet. An induced current will appear in the coil

1) only if the coil is stationary relative to the magnet

2) only if the coil is placed on a magnet

3) only if the coil is removed from the magnet

4) if the coil is put on or removed from the magnet

According to the law of electromagnetic induction, an induced current appears in a circuit when the magnetic flux through the circuit changes. It does not matter what the reason for the change is; it can be the movement of the magnet relative to the circuit, or the movement of the circuit relative to the magnet. It also does not matter how the flux changes, whether it increases or decreases, this only determines the direction of the induction current. Since in the conditions of the problem the magnet is stationary, the induced current can be observed by putting the coil on the magnet or removing it from it. Statement 4 is true.

Physics test The phenomenon of electromagnetic induction for grade 11 with answers. The test includes 2 options. Each option contains 5 tasks.

1 option

1. v in a uniform magnetic field as shown in Figure 35. What charges are formed at the edges of the rod?

A. 1 - negative, 2 - positive.
B. 1 - positive, 2 - negative.

2. A magnet is inserted into the short-circuited coil quickly the first time, and slowly the second time. In which case is the charge transferred by the induction current greater?

A. In the first case, the charge is greater.
B. In the second case, the charge is greater.
B. In both cases the charges are the same.

3. In a magnetic field with an induction of 0.25 T, a conductor 2 m long moves perpendicular to the induction lines at a speed of 5 m/s. What is the induced emf in the conductor?

A. 250 V.
B. 2.5 V.
V. 0.4 V.

4. In 3 s, the magnetic flux penetrating the wire frame uniformly increased from 6 Wb to 9 Wb. What is the value of the induced emf in the frame?

A. 1 B.
B. 3 V.
V. 6 V.

5. In what direction of movement of the circuit in a magnetic field (Fig. 36) does an induced current appear in it?

A. When moving in the drawing plane to the right.
B. When moving in the plane of the drawing away from us.
AB.

Option 2

1. The metal rod moves at a speed v in a uniform magnetic field as shown in Figure 37. What charges are formed at the edges of the rod?

A. 1 - negative, 2 - positive.
B. 1 - positive, 2 - negative.
B. A definite answer cannot be given.

2. A magnet is inserted into the short-circuited coil quickly the first time, and slowly the second time. In which case is the work done by the emerging emf greater?

A. In the first case, there is more work.
B. In the second case, there is more work.
Q. In both cases the work is the same.

3. In a magnetic field with an induction of 0.5 T l, a conductor 0.5 m long moves perpendicular to the induction lines at a speed of 4 m/s. What is the induced emf in the conductor?

A. 100 V.
B. 10 V.
V. 1 V.

4. In 2 s, the magnetic flux penetrating the wire frame uniformly decreased from 9 Wb to 3 Wb. What is the value of the induced emf in the frame?

A. 4 B.
B. 3 V.
V. 2 V.

5. In what direction of movement of the circuit in a magnetic field (Fig. 38) does an induced current appear in it?

A. When the drawing plane moves to the right.
B. When the drawing plane moves away from us.
B. When turning around the side BD.

Answers to the physics test The phenomenon of electromagnetic induction for grade 11
1 option
1-B
2-B
3-B
4-A
5-V
Option 2
1-B
2-A
3-B
4-B
5-V

Physics problem - 4083

2017-09-30
A magnet is inserted into a short-circuited coil: once quickly and once slowly. Does the same charge flow through the circuit in both cases? Is the same amount of heat released?

Solution:

Let the coil resistance be $R$. If over a short period of time $\Delta t$ the magnetic flux through the circuit changes by $\Delta \Phi$, then an induced emf $\mathcal(E)_(i) = - \frac( \Delta \Phi) appears in the coil )( \Delta t)$. Induction current $I = \frac( \mathcal(E)_(i))(R) = - \frac(1)(R) \cdot \frac( \Delta \Phi)( \Delta t)$. During the time $\Delta t$, a charge $\Delta q = I \Delta t = - \frac( \Delta \Phi)( R)$ passes through the circuit. The total charge passing through the circuit $q = \sum \Delta q = - \frac(1)(R) \sum \Delta \Phi = - \frac( \Phi)(R)$. Here $\Phi$ is the final value of the magnetic flux (the initial value is zero). This means that $q$ does not depend on the speed of the process. The amount of heat $Q$ released in the circuit is equal to the work of external forces: $Q = q \mathcal(E)_(i)$. Since the charge $q$ is the same in both cases, and $\mathcal(E)_(i)$ is greater when the magnet moves quickly, the amount of heat in the first case is greater. This conclusion can be reached in another way: $Q = A = Fs$, where $A$ is the action taken when a magnet is introduced mechanical work. The movement of the magnet $s$ is the same in both cases, and $F$ is greater in the first case ($F$ is the force of repulsion of the magnet from the coil due to the appearance of induced currents).
Answer: the charge is the same; the amount of heat is greater when the magnet moves quickly.

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