Suppose a uniformly charged wall provides a uniform electric field of 2 × 10 4 N C - 1 normally. A charged particle of mass 2 g being suspended through a silk thread of length 20 cm and remain stayed at a distance of 10 cm from the wall. Then the charge on the particle will be 1 x μ C where x = ________ [use g = 10 m s - 2 ]

Step-by-step solution

As we can see from geometry, sin θ = 10 20 = 1 2 ⇒ θ = 30 ° Vertical component of tension will balance the weight and the horizontal component will balance the electric force. Therefore, tan θ = q E m g ⇒ tan 30 ° = q × 2 × 10 4 2 × 10 - 3 × 10 ⇒ 1 3 = q × 10 6 ⇒ q = 1 3 × 10 - 6 C = 1 3 μC Hence, x = 3 .