Puzzle Time!

123456
Across
  1. 4. rod Positive terminal of the cell
  2. 6. The difference in the amount of energy between two points in a circuit.
Down
  1. 1. Unit current is a ---------- quantity
  2. 2. S.I Unit of electric current
  3. 3. whitish, metal layer upon opening a dry cell
  4. 5. SI Unit of potential difference