Work may be measured using units of A.watts B.newton C.joules D.newtons per second
1 answer:
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<h3><u>Given</u> :</h3>
Current flow light bulb = 2.5
Resistance of light bulb = 3.6Ω
<h3><u>To Find </u>:</h3>We have to find voltage of battery
➠ As per ohm's law, current flow through a conductor is directly proportional to the applied potential difference.
➝ V ∝ I
➝ <u>V = I × R</u>
Where, R is the resistance of conductor.
⇒ V = I × R
⇒ V = 2.5 × 3.6
⇒ <u>V = 9 volt</u>
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:
where is the emf induced and
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
where
B is the magnitude of the magnetic field
A is the surface area
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.