Hey guys,
just need a few expainations for questions I don't understand
Question1
Question 2
Question 3
Cheers
1)
back emf is related to law of conservation of energy (due to Lenz's law of the currents running through a coil)
voltage transformation is related to law of conservation of energy (P
IN=P
OUT)
escape velocity, point where |final E
p|=initial E
k - this is essentially related to the law of conservation of energy , where the intial kinetic energy of the object is equal to the final GPE
.'. by process of elimination, the answer is A
2)
F=qvBsin(x)
F is proportional to q and B
.'. A and B are not the answer
now, if we have a velocity vector, it can be broken up into two parts; a vertical component and a horizontal component. we know by the right hand palm rule that if the velocity is parallel to the magnetic field, then the force will be zero. thus, we can deduce that the parallel component of the velocity will have NO effect on the force acting on the particle.
.'. the answer is C