1 An electric current is the overall movement of charged particles in one direction. 2  To obtain an electric current, there needs to be a continuous circuit from one terminal of a battery to the other. 3  An electric current in a circuit transfers energy from the battery to the circuit components.
A pea gravel walkway or patio costs about $5 per square foot, installed, including a layer of base rock. If you'd like to install it yourself, it will cost half as much.Add in the cost of a header or Bender Board. A wood header is about $5 per linear foot; a metal header is $6 (black metal disappears well).You won't need a header if you're installing gravel against a house, fence, or raised bed.dd in the cost of a header or Bender Board. A wood header is about $5 per linear foot; a metal header is $6 (black metal disappears well). You won't need a header if you're installing gravel against a house, fence, or raised bed.
Expert Advice: To determine how much sand (or gravel) you'll need for a paver walkway, multiply the path length (in feet) by width (in feet) and then multiply by the desired depth of sand (in feet) to determine cubic feet.Divide by 27 to determine cubic yards.ravel Walkway. This gravel walkway is an inexpensive and informal option for getting around a yard. You can make a gravel path any width, depending on whether it will be used for solitary strolling or for walking side by side. 1  Get quotes for a new walkway from professionals in your area.