What happens to the dirft velocity `(v_d)` of electrons and to the resistance (R), if the length of a aconductor is doubled (keeping potential difference unchanged)?

What happens to the potential energy if the height of a body is doubled?

How does drift velocity of electrons in a metallic conductor change, if the length of the conductor is doubled by stretching it, keeping the applied voltage constant?

How does the mobility of electrons in a conductor change, if the potential difference applied across the conductor is doubled keeping the length and temperature of the conductor constant.

What happens to the power dissipation if the value of electric current pasisng through a conductor of a constant resistance is doubled?

A bulb whose resistance is 10 ohm is connected to a 6 V battery. Calculate the potential difference across the bulb.

What is the de-Broglie wavelength of an electron beam accelerated through a potential difference of 25 V?