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A charged oil (density 880 ~kg ~m ⁻³ ) drop is held stationary between two parallel horizontal metal plates 6.0 mm apart when a potential difference of V =103 volt is applied between the two plates. When the electric field is switched off, the drop falls. At a certain time the drop is seen to fall a distance of 2.0 mm in 35.7 s and next 1.2 mm in 21.4 s . (The upper plate in the experiment is at higher potential). Gi

Options

  1. AThe radius of the drop is a =7.25 10⁻⁷ ~m
  2. BThe charge on the drop is q =8.0 10⁻¹⁹ C
  3. CThe terminal velocity of the oil drop, under its free fall, is 5.6 10⁻⁵ ~ms ⁻¹
  4. DThe oil drop carries 5 excess electrons

Correct answer

D. The oil drop carries 5 excess electrons

Step-by-step solution

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