Question

1. Given that a certain galvanometer has an internal resistance of 254 N and can handle a maximum current of 250 A, design an ammeter capable of reading at full- scale deflection (the maximum current without burning up the meter) 10 A and a voltmeter capable of reading at full-scale deflection 10 V. Assume that the space available in the meter for the shunt (for the ammeter) or limiting (for the voltmeter) resistor is no more than 5 mm in length and it mm2 in cross-sectional area. State specifically what material and dimensions you are using for the both resistors. Your shunt and limiting resistors chosen must be within 45% of your calculated values.

Answer 1

1.) internal resistance of the galvanometero p = 2542 maximum current iman = 250 MA = 250x10-6 A Ammeter: 10 A Y f(lo-iman.) G measured Current ww Rs (shunt) voltage between, Rg Voltage between galvanometer, Maximum, iman (10 -- Iran) (otherwise, galvanome . Current thrrough Rs RS iman so (10-iman) will be byooned) 250 x 106 x 254 F10-10-4x250)1 2 How space for shunt given, Aroen, Imm²=A = 6.35 x 10-3 2 2 and length, I = 5mm Rs = 2 A (s resistivity of choosen material) -) fg = Rs 4 ㅈ 6.35810-3 T X 10 3 22. m 3.99 x10-6 shim so, we choose a material such that, which have resistivity close to calculated Is value. Voltmeter : iman Re Gr V=10V limiting resistance, Reso, equivalent resistance - Retro Now, curment through voltmeter aiman, giorno peito) - Re-iman 10 -T =397462 24.97 Rim - Se=24.95 2.m we have to Se=Rp. A choose a material which have resistivity close to se calculated.