A V = 140-V battery is connected across two parallel metal plates of area 28.5 c

Question

A V = 140-V battery is connected across two parallel metal plates of area 28.5 cm2 and separation 8.00mm . A beam of alpha particles (charge +2e, mass 6.64*10*27 kg) is accelerated from rest through a potential difference of 1.60kV and enters the region between the plates perpendicular to the electric field, as shown in the figure.(Figure 1)

What magnitude of magnetic field is needed so that the alpha particles emerge undeflected from between the plates?

B=?

A V = 140-V battery is connected across two parallel metal plates of area 28.5 cm2 and separation 8.00mm . A beam of alpha particles (charge +2e, mass 6.64*10*27 kg) is accelerated from rest through a potential difference of 1.60kV and enters the region between the plates perpendicular to the electric field, as shown in the figure.(Figure 1) What magnitude of magnetic field is needed so that the alpha particles emerge undeflected from between the plates? B=?

Explanation / Answer

KE = PE

0.5 mv^2 = eV

or v = sqrt(2eV/m)

v = sqrt(2*2*1.6e-19 * 1600/6.64e-27)

v = 3.92*10^5 m/s
--------------------------------------------------

now use E = V/d = (1600-140)6/8e-3

E = 1.82*10^5 N/C

so finally apply

E/B = V

so B = E/V = 1.82e5/3.92 e5

B = 0.465 Tesla

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.