krypticlemonjuice
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Why is the answer to this q (b)?
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Why is the answer to this q (b)?
SB257426
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When a proton or any other charged particle enters a magnetic field, its velocity remains unchanged. You can confirm this by doing a bit of equating:
F(B) = F(C) [equating centripedal force to force due to magnetic field because a charged particle moves in circular motion when it enters a magnetic field]
qvb = (mv^2)/r
the 'v' in both equations is the same..... essentially the particle just travels in centripedal motion with the same velocity. Thus as it exits the field, velocity will be the same
Extra: Equation F(B) = F(C), allows us to find the radius of orbit and can also help determine the period of motion, that is, the time it takes for a charged particle to complete one revolution around a cirle in a magnetic field. Note: heavier particles, such as an alpha particle, will have a greater radius
F(B) = F(C) [equating centripedal force to force due to magnetic field because a charged particle moves in circular motion when it enters a magnetic field]
qvb = (mv^2)/r
the 'v' in both equations is the same..... essentially the particle just travels in centripedal motion with the same velocity. Thus as it exits the field, velocity will be the same
Extra: Equation F(B) = F(C), allows us to find the radius of orbit and can also help determine the period of motion, that is, the time it takes for a charged particle to complete one revolution around a cirle in a magnetic field. Note: heavier particles, such as an alpha particle, will have a greater radius
howcanibesmarter
Well-Known Member
Because it undergoes uniform circular motion, and in uniform circular motion, the velocity is changing but the speed is constant, meaning only direction is changing
Remember there are always 3 cases. When theta (angle between velocity of charge and magnetic field) is 0, meaning field is parallel, F=0. When theta is 90 degrees, which is this case it undergoes uniform circular motion (because the force by RHPR is always perpendicular to motion). When theta is between 0 and 90, helical motion will occur
Remember there are always 3 cases. When theta (angle between velocity of charge and magnetic field) is 0, meaning field is parallel, F=0. When theta is 90 degrees, which is this case it undergoes uniform circular motion (because the force by RHPR is always perpendicular to motion). When theta is between 0 and 90, helical motion will occur