1) It may seem strange that the selected velocity does not depend on either the
ID: 1545836 • Letter: 1
Question
1) It may seem strange that the selected velocity does not depend on either the mass or the charge of the particle. (For example, would the velocity of a neutral particle be selected by passage through this device?) The explanation of this is that the mass and the charge control the resolution of the device--particles with the wrong velocity will be accelerated away from the straight line and will not pass through the exit slit. If the acceleration depends strongly on the velocity, then particles with just slightly wrong velocities will feel a substantial transverse acceleration and will not exit the selector. Because the acceleration depends on the mass and charge, these influence the sharpness (resolution) of the transmitted particles.
Assume that you want a velocity selector that will allow particles of velocity v to pass straight through without deflection while also providing the best possible velocity resolution. You set the electric and magnetic fields to select the velocity v . To obtain the best possible velocity resolution (the narrowest distribution of velocities of the transmitted particles) you would want to use particles with __________.
a) both q and m large
b) q large and m small
c) q small and m large
d) both q and m small
2) A proton, with mass 1.67 × 10-27 kg and charge +1.6 × 10-19 C, is sent with velocity 7.1 × 104 m/s in the +x direction into a region where there is a uniform electric field of magnitude 730 V/m in the +y direction. Assume that the magnetic field has no x-component and neglect gravitational effects.
a) What is the magnitude and direction of the uniform magnetic field in the region, if the proton is to pass through undeflected?
b) What is the direction of the uniform magnetic field in the region, if the proton is to pass through undeflected?
3) The Hall voltage across a conductor in a 58 mT magnetic field is 2.0 V . When used with the same current in a different magnetic field, the voltage across the conductor is 2.5 V . What is the strength of the second field?
4) Consider the solenoid shown in the figure.
a)Will there be an induced current if magnet 1 is moved away from the solenoid?
b) What about if magnet 2 is moved away from the solenoid? Will there be an induced current?
5) In this problem, you will use Lenz's law to explore what happens when an electromagnet is activated a short distance from a wire loop. You will need to use the right-hand rule to find the direction of the induced current. Finally, the switch on the electromagnet is reopened. The magnitude of the external magnetic flux through the wire loop ______ (A. increases, B. decreases, C. remains constant), and there is _______ (A. zero, B. a clockwise, C. a counterclockwise) current induced in the loop (as seen from the left).
O z direction direction z direction O -z direction one of the aboveExplanation / Answer
1) from newtons law
f = ma
a = f/m
f = qE
q large and m small
2) negative z direction
f = qE
f = qv*B
3) V = B.I / (nqt)
V1 / V2 = B1 / B2
B2 = B1(V2 / V1) = 72.5 mT
4)yes
b) no
5) decreases and clockwise
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.