Paschen's Law predicts the breakdown voltage (V) as a function of the pressure distance product (Pd) and is often written as:

  

i) ii) Vb BPd In(APd)In(In(1+)) = f (Pd) Where A and B are constants with A = and B = AV. AP Explain the meaning of terms, , y and V The Paschen curve, represented by the function f above, has a minimum value in the breakdown voltage Vb-min at a corresponding value of the pressure-distance product (Pd)min. By setting the first derivative of Vb with respect to Pd to zero, the minimum value of the function f can be found. Using this technique show that ---) (Pd)min = ln (1 + A