A wire of 5Ω resistance is drawn out so that its new length is two times the original length. If the resistivity of the wire remains the same and the cross-sectional area is halved, the new resistance is
An electron of charge 1.6 x 10-19C is accelerated between two metal plates. If the kinetics energy of the electron is 4.8 x 10-17J, the potential difference between the plate is
