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Concepts Of Physics MCQ Edition [Volume 2]PhysicsElectric Current through Gases

The plate current in a triode can be written as i_p = k ! (V_g + V_p )^ 3/2 . The mutual conductance is proportional to what power of the plate current?

Options

  1. A2 3
  2. B1 3
  3. C1 2
  4. D3 2

Correct answer

B. 1 3

Step-by-step solution

The plate current in a triode is given by: i_p = k (V_g + V_p )^ 3/2 The mutual conductance g_m is defined as the rate of change of plate current with respect to grid voltage at a constant plate voltage: g_m = i_p V_g Differentiating the given expression with respect to V_g : g_m = 3 2 k (V_g + V_p )^ 1/2 From the equation for plate current, we can write: (V_g + V_p )^ 3/2 = i_p k (V_g + V_p )^ 1/2 = ( i_p k )^ 1/3 Substituting this back into the expression for mutual conductance: g_m = 3 2 k ( i_p k )^ 1/3 g_m = 3

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