-- Change the battery to one with higher voltage.
-- Wrap more turns of wire around the spike.
-- If the spike is made of anything else but iron, replace it with a pure iron one.
Answer: Power of a lens is -2D, negative sign indicates it is a Concave lens. Focal length (in meters)=1/power of the lens, thus focal length=1/2=0.5m=50cm.Jul 6, 2019
Electrons are found in shells or orbitals that surround the nucleus of an atom