Answer to Question #61333 in Electricity and Magnetism for muhammad umar

Question

16 Which of the following correctly gives the electric field at the centre of a uniformly charged semicircular arc of radius
a
and charge per unit length,
λ
?
a) λ2πϵ0a

b) 2λπϵ0a

c) λπϵ0a2

d) λπϵ0a
15) A uniform electric field of 200 N/C is in the x-direction. A point charge of
3μC
is released from rest at the origin. What is the kinetic energy of the charge when it is at x = 4 m?

a) 2.4×10−2J

b) 1.6×10−2J

c) 3.6×10−2J

d) 4.8×10−2J