Question

A unit positive charge is moved along the circumference of a circle of radius, r with a -5C μ C charge at the centre of the circle. Then, the work is done in the process is __________.
(A) negative work of 100J
(B) positive work of 100J
(C) zero
(D) Q.1 / 4π ∈₀ .r

Answer 1

Answer:

(a). Mass of the Body = 10 kg. Height = 10 m. Acceleration due to gravity = 9.8 m/s². Using the Formula,Potential Energy = mgh  = 10 × 9.8 × 10 = 980 J. (b). Now, By the law of the conservation of the Energy, Total amount of the energy of the system remains constant. ∴ Kinetic Energy before the body reaches the ground is equal to the Potential Energy at the height of 10 m. ∴ Kinetic Energy = 980 J. (c). Kinetic Energy = 980 J. Mass of the ball = 10 kg. ∵ K.E. = 1/2 × mv² ∴ 980 = 1/2 × 10 × v² ∴ v² = 980/5 ⇒ v² = 196 ∴ v = 14 m/s. 

Answer 2

Answer:

(A) option is your answer.