Answer:
fem = -A β
Explanation:
Faraday's law gives the induced electromotive source (emf)
fem =
the magnetic flux is
= B. A = B A cos θ
the bold are vectros. In this case the normal to the ring is parallel to the magnetic field so the angle is zero cos 0 = 1, also the area of the ring is constant
fem = -A
we carry out the derivative of the function B = α + β t
fem = -A β
so we see that there is an electromotive force in the ring.
Answer:
4.79 J
Explanation:
The energy of a single photon is given by
where
is the Planck constant
f is the frequency of the photon
Here we have
so the energy of one photon is
Here we have 1 mol of photons, which contains
photons (Avogadro number). So, the total energy of this mole of photons is:
Answer:
the force of attraction between the two charges is 4.2 x 10⁹ N.
Explanation:
Given;
the magnitude of first charge, q₁ = 0.06 C
the magnitude of the second charge, q₂ = 0.07 C
distance between the two charges, r = 3 m
The force of attraction between the two charges is calculated as ;
where;
k is Coulomb's constant = 9 x 10⁹ Nm²/C²
Therefore, the force of attraction between the two charges is 4.2 x 10⁹ N.