1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Ivenika [448]
2 years ago
13

True or false?

Physics
1 answer:
Ksju [112]2 years ago
5 0

1. False

Explanation: it's exactly the opposite. In fact, Lenz's law states that the induced current and the induced emf in a conductor are generated in such a direction that opposes to the change in magnetic flux through the coil. This is summarized by the negative sign in the Faraday's Newmann Lenz law:

\epsilon= -\frac{d\Phi }{dt}

where \epsilon is the emf induced and \frac{d\Phi}{dt} is the rate of change of magnetic flux through the coil.

Lenz's law is a consequence of the law of conservation of energy. In fact, we have:

- If the magnetic flux through a coil is increasing, then the induced current has a direction such that the magnetic field generated by the coil is opposite to the direction of the external magnetic field, in order to decrease the total flux

- If the magnetic flux through a coil is decreasing, then the induced current has a direction such that the magnetic field generated by the coil is in the same direction as the external field, in order to increase the total flux

2. False

Explanation: the magnetic flux through a surface is given by

\Phi = BA cos \theta

where

B is the magnitude of the magnetic field

A is the surface area

\theta is the angle between the direction of B and the normal vector to the surface

As we see, the magnetic flux depends not only on B and A, but also on the orientation of the coil with respect to the magnetic field.

3. False

Explanation:

- Sound waves are mechanical waves: mechanical waves are waves consisting of oscillations of the particles in a medium. Due to their nature, therefore, mechanical waves can propagate only in the presence of a medium

- Electromagnetic waves are NOT mechanical waves: they consist of oscillations of electric and magnetic fields, in a direction perpendicular to the direction of propagation of the wave. Since em waves are not mechanical waves, they do NOT need a medium to propagate, since they can also travel through a vacuum; therefore the original statement is false.

You might be interested in
How are gas particles arranged in a container?
joja [24]

Answer:

3. Tightly Packed

Explanation:

Hope this helps

I learned this

4 0
3 years ago
Read 2 more answers
A parallel-plate capacitor has a voltage of 391 v applied across its plates, then the voltage source is removed. what is the vol
andrezito [222]

When the capacitor is connected to the voltage, a charge Q is stored on its plates. Calling C_0 the capacitance of the capacitor in air, the charge Q, the capacitance C_0 and the voltage (V_0=391 V) are related by

C_0 =\frac{Q}{V_0} (1)


when the source is disconnected the charge Q remains on the capacitor.


When the space between the plates is filled with mica, the capacitance of the capacitor increases by a factor 5.4 (the permittivity of the mica compared to that of the air):

C=k C_0 = 5.4 C_0

this is the new capacitance. Since the charge Q on the plates remains the same, by using eq. (1) we can find the new voltage across the capacitor:

V=\frac{Q}{C}=\frac{Q}{5.4 C_0}

And since Q=C_0 V_0, substituting into the previous equation, we find:

V=\frac{C_0 V_0}{5.4 C_0}=\frac{V_0}{5.4}=\frac{391 V}{5.4}=72.4 V



7 0
3 years ago
You know the power for a machine and the time it takes to produce that power, what value can you calculate?
Sati [7]

We can calculate the work done by the machine by the mathematical formula,

P = W/t

where, P = Power

W = work done

t = time

6 0
2 years ago
How is it possible for a single sedimentary rock to contain rock particles animal shells and minerals that crystallized from wat
shutvik [7]
"Sedimentary rocks are types of rock that are formed by the deposition of material at the Earth's surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic particles (detritus) to settle and accumulate or minerals to precipitate from a solution."
7 0
3 years ago
Read 2 more answers
If 35 mg of Oxygen is mixed with 1000 g of water at 25 degrees Celsius, a solution forms.
Serjik [45]

Answer:

The solute is oxygen

The solvent is water

Explanation:

A solvent is any chemical substance that dissolves other chemical substances, while a solute refers to any chemical substance that dissolves in other chemical substances. The best way to know when a chemical substance dissolves in another chemical substance is when a solid or gas dissolves in water. The solid or the gas can now be referred to as the solute and it will be shown to be in the the aqueous state, while the solvent is usually shown to be in the liquid state in any chemical equation.

Let us use the particular example of the dissolution of oxygen gas in water as shown below;

O2(g) + H2O(l)⇄O2(aq) + H2O(l)

The aqueous oxygen is the solute while the liquid water is the solvent.

Also, the substance having a smaller mass must be the solute and the substance having the larger mass must be the solvent.

3 0
3 years ago
Other questions:
  • 2. While standing near a bus stop, a student hears a distant horn beeping. The frequency emitted by the horn is 440 Hz. The bus
    5·1 answer
  • What is the shortest distance d you need to walk forward to be at a point where you cannot hear the speakers? the forward direct
    15·2 answers
  • How does science help society?
    14·2 answers
  • ________are muscles connected to the skeleton.
    6·1 answer
  • What is one of Kepler's laws of planetary motion?
    11·1 answer
  • When electrical energy is being used by an electric light, what really happens to the energy?
    5·2 answers
  • A proton is moving toward a second, stationary proton. What happens as the protons get closer?
    12·1 answer
  • A voltage of 75 V is placed across a 150 Ω resistor. What is the current through the resistor?
    12·1 answer
  • If a 16 N net force makes an object accelerate at 4 m/s2, what is the mass of the object?
    12·1 answer
  • what will be the focal lenght of a combined lens made by contact of two lenses of power +3D and -2D.​
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!