The dome of a van de graaff generator has a diameter of 30 cm and is at a potential of +20 000V. Calculate : a) the charge on the dome b) the electric field strength at the surf…

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asked Sep 24, 2019 24.4k views

1 Answer

Realnero · Answer 1 · 2019-09-30T02:24:57+0000

a) radius of the dome r=15 cm

Potential, V=20,000 V

$V=(Q)/(4\pi\epsilon_o r)$

here Q is charge,
$\epsilon_o$ is permitivity of vacuum and r is the distance from the charge.

$\Rightarrow Q=V*4\pi\epsilon_o r$

$\Rightarrow Q= 20,000*4*3.14*8.85*10^(-12)*0.15=3.33*10^(-7)C$

b) Electric field (E) strength at the surface of the dome is given by:

$E=(V)/(r)\\ \Rightarrow E=(20,000)/(0.15)=1.33*10^(5)V/m$

c)force on the proton near the surface of the dome:

F=qE

where E is the electric field and q is the charge of proton.

charge of a proton
q=1.6*10^(-19)C

F=1.6*10^(-19)*1.33*10^(5)=2.218*10^(-14)N