Lecture 14 Test 1

QUESTION 1

A velocity selector in a mass spectrometer uses a 0.351-T magnetic field.
What electric field strength is needed to select a speed of 7.52×10⁶m/s?
Input your results in N/µC using 3 significant figures.

Solution

v = 7.52×10⁶m/s

B = 0.351 T

E = ?

Main Formula for the solution:

vB = E

Calculation

Google:

0.351 T * 7.52×10^6m/s in N/ µC
or
(0.351 T) * 7.52E6 (m / s) in N/ microcoulombs
Round the result as "2.64".

QUESTION 2

A charged particle moves along a circle of radius r = 306 mm in a uniform magnetic field B = 29.1 mT. Find its velocity in m/s if that particle is a proton.
Input your results in m/s using 3 significant figures.

Symbolic Solution:

v = rqB/m

Calculation

Google:

306 mm * 29.1 mT *1.602*10^-19C / (1.6726*10^-27 kg) in m/s
or
306 mm * 29.1 mT *1.602E-19C / (1.6726E-27 kg) in m/s


Do not enter Google's solution "852873.921". Round as "853000".

www.wolframalpha.com:

306 mm * 29.1 mT * electric charge of proton / mass of proton
wolframalpha.com