Both have positive charge. In fact, an alpha particle IS a nucleus of a Helium atom.
<span>Whatever the focus of the experiment is, plus any others factors that might influence the outcome of the experiment. If you are testing a new cancer drug, the experimental group and the control group must both be people with the same type of cancer, and both be a representative distribution of the population, all races, genders, ages, etc. You want the only difference in the two groups to be what you are studying, i.e. the effects of the drug.</span>
Answer:
Rate of change of magnetic field is
Explanation:
We have given diameter of the circular loop is 13 cm = 0.13 m
So radius of the circular loop 
Length of the circular loop 
Wire is made up of diameter of 2.6 mm
So radius 
Cross sectional area of wire 
Resistivity of wire 
Resistance of wire 
Current is given i = 11 A
So emf 
Emf induced in the coil is 


Because of how it's worded the answer would most likely be number four
Concave makes things smaller and convex makes things bigger