Ammeter connected directly across a voltage source since their internal resistance is very low and excess current would flow. Ammeters are designed for a low voltage drop across their terminals, much less than one volt; the extra circuit losses produced by the ammeter are called its "burden" on the measured circuit. Ordinary Weston-type meter movements can measure only milliamperes at most, because the springs and practical coils can carry only limited currents. To measure larger currents, a resistor called a "shunt" is placed in parallel with the meter. The resistances of shunts is in the integer to fractional milliohm range. Nearly
Becky Measures Becky Measures Becky Measures (born 13 October 1981 in Derbyshire, England), from Bakewell, Derbyshire, is a radio presenter on Peak FM, an independent local radio station in Derbyshire and a professional charity fund-raiser. She held a variety of jobs including being an extra for the locally filmed television series "Peak Practice" before moving into radio. In 2004, Measures, then 23, decided to have a double mastectomy after a genetic test revealed that she had an 80 to 90 per cent risk of developing breast cancer. Both her mother and a cousin, Helen, had suffered from the same illness. To help