Numericals on Current and Dual nature
1) When a steady current flows through a conductor of non uniform cross section which of the quantities remains constant a) Current b) current density c) electric field d) drift speed a) we know that I=Q/ t so current is independent of area of cross section b) current density j = I / A ie current density is inversely proportional to area of cross section c) electric field E = V / l E=IR / l E=(Iρl) /Al E=Iρ / A so E is inversely proportional to area of cross section d) V d =I / nAe so the drift speed is inversely proportional to area of cross section. 2) The fig shows a plot between 1/ √ V, where V is the accelarating potential Vs de Broglie wave length λ in the case of two particles having same charge q but different masses m 1 and m 2 with lines A and B which one will have smaller mass λ =h/p =h / ( √ 2mK) λ=h/ ( √ 2mqV) λ=h/ ( √ 2mq) ×(1/ √ V ) (1/ √ V )=( √ 2mq) /h × λ slope of the given graph is ( √ 2mq ) / h slope of A is more