HOIR?NBỊ2(R2 + z?)z3'1. Starting with the above equation, derive an expression for the magnetic field at the midpoint of theHelmholtz coils.2. Find an expression for the speed of the electrons accelerated through a potential difference Vace-3. Find an expression for the charge to mass ratio, e/m, in terms of v, B, r, by applying Newton's 2ndlaw to an electron in circular motion.4. Combine 2 and 3 to get an expression for e/m in terms of Vace,r, and B. Figure 1: CRT with coils in Helmholtz configuration.The hot cathode emits electrons which are then accelerated through potential difference Vacc. Whenthe electrons enter the magnetic field B, which is perpendicular to their velocity, they move on a circularpath with radius r. The magnetic field is due to coils in Helmholtz configuration (2 coils separateddistance that equals their radius).The magnetic field due to one of the coils with radius R, at a point on the axis distance z away from thecenter of the coil, was found using the Biot-Savart law:HOIR?NB12(R2 + z2)ž

At the center of coil z=0 The equation will reduce to : B = n μoI2R V= W/q q for electron = e W =…

HoIR?N B1 3 2(R2 + z²)7 1. Starting with the above equation, derive an expression for the magnetic field at the midpoint of the Helmholtz coils. 2. Find an expression for the speed of the electrons accelerated through a potential difference Vace: 3. Find an expression for the charge to mass ratio, e/m, in terms of v, B,r, by applying Newton's 2nd law to an electron in circular motion. 4. Combine 2 and 3 to get an expression for e/m in terms of Vacc,r, and B.

HoIR?N B1 3 2(R2 + z²)7 1. Starting with the above equation, derive an expression for the magnetic field at the midpoint of the Helmholtz coils. 2. Find an expression for the speed of the electrons accelerated through a potential difference Vace: 3. Find an expression for the charge to mass ratio, e/m, in terms of v, B,r, by applying Newton's 2nd law to an electron in circular motion. 4. Combine 2 and 3 to get an expression for e/m in terms of Vacc,r, and B.

Glencoe Physics: Principles and Problems, Student Edition

1st Edition

ISBN:9780078807213

Author:Paul W. Zitzewitz

Publisher:Paul W. Zitzewitz

Chapter26: Electromagnetism

Section26.1: Interactions Of Electric And Manetic Fields And Matter

Problem 2PP

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