Two wires A and B made of same material having length 10 cm and 40 cm respectively are connected in parallel to the same source of emf 10 V . What will be the ratio of the drift velocity of the electrons in the wire A to the drift velocity in the wire B ?

Step-by-step solution

The drift velocity v_ d of electrons in a conductor is given by the formula v_ d = I neA , where I is the current, n is the electron density, e is the elementary charge, and A is the cross-sectional area. Since the wires are made of the same material, n is the same for both. The current I in a wire is given by I = V R , where V is the potential difference and R is the resistance. The resistance R is given by R = l A , where is the resistivity and l is the length. Substituting this into the expression for current, I