Currently, one major disadvantage of renewable energy resources is that renewable energy resources<span> are more expensive
than fossil fuels.
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d. are more expensive
In physics we refer to how heavy the object is as the mass.
Fg = mass x acceleration due to gravity
Force is directly proportional to mass, thus if force of gravity increases mass also increases.
Answer:
Semi conductors are part of the fourth group in periodic table.
Explanation:
Periodic table is the arrangement of chemical elements on the basis of their atomic number. So all the elements with respective valence electrons are placed in thir respective groups. . All the elements with valence electrons four are placed in the fourth group .Semi conductors is the common name given to the elements of 4th group. These elements dont have the tendency to either donate or accept.
The group 3 elements have three electrons in their valence shell and hence have a tendency to donate. Whereas the group 5 elements having five valence electrons accept to satisfy thir octet. The semi conductors exist between 3rd and 5th groups exhibiting different properties according to the temperatures and excitations provided.
<h2>
C. 20 T</h2>
The strength of the magnetic field is equal to 20 Tesla.
<h3>
Explanation:</h3>
Given:
Induced potential difference = V = 12 V
Length of wire = L = 0.20 m
Speed of the moving wire = V = 3.0 m/s
Magnetic field strength = B = ?
A conductor, placed in a uniform magnetic field; when moved at a constant speed with respect to the field, leads to a changing magnetic flux, generating an electromotive force (EMF). Using, Faraday's law of magnetic induction, a moving conductor's induced EMF in terms of the magnetic field strength is given by :
......................(1)
where
E = Induced potential difference (EMF)
L = Length of the conductor
V = Speed of the conductor moved with respect to the magnetic field
B = Strength of uniform magnetic field
Rewriting equation (1) for B, we get

The strength of magnetic field is equal to 20 Tesla.
The electrostatic force is directly proportional to the product of the charges, by Coulomb's law.
F α Qq
If the charges are now half the initial charges:
<span>F α (1/2)Q *(1/2)q
</span>
F α (1/4)Q<span>q
The new force when the charges are each halved is (1/4) the first initial force experienced at full charge.</span>