Lowers Recommended Lead-Level Limits in Children. For the first time in 20 years, federal health authorities have lowered the recommended limit for lead exposure in young children, which they say could add 200,000 children to those believed to have unsafe lead levels in their blood.
Electrical Units of Measure. The standard SI units used for the measurement of voltage, current and resistance are the Volt [ V ], Ampere [ A ] and Ohm [ Ï ] respectively.
Resistance is a measure of how much an object opposes the passage of electrons. The unit of electrical resistance is the ohm and it is represented by Ï. Every material has Resistance. Copper has a low resistance and wood has a high resistance. For example, a metre of copper has a resistance of only 1 Ohm but a metre of wood has a resistance of 10000000 ohm.