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Manipal MET2017PhysicsCurrent Electricity

An electron at rest is accelerated through a potential difference of 200 V . If the electron acquires a velocity of 8.4 10^8 ~cm / s , its e m ratio is

Options

  1. A1.76 10¹¹ C / kg
  2. B2.5 10^9 C / kg
  3. C1.5 10^5 C / kg
  4. D9.8 10^3 C / kg

Correct answer

A. 1.76 10¹¹ C / kg

Step-by-step solution

aligned & 1 2 m v^2=e V & e m = v^2 2 V aligned Given, V=200 volt, v=8.4 10^8 ~cm / s =8.4 10^6 ~m / s e m = (8.4 10^6 )^2 2 200 =1.76 10¹¹ C / kg

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