(a) Explain what a “thermoelectric potential” is. Discuss the circumstances in which thermoelectric potentials do and do not cause problems in electrical circuits. (b) Why does a voltmeter load an...

(a) Explain what a “thermoelectric potential” is. Discuss the circumstances in which

thermoelectric potentials do and do not cause problems in electrical circuits.

(b) Why does a voltmeter load an electric circuit when it is placed into it to

measure a voltage value and what is the effect of this loading?

(c) Suppose that the components in the circuit shown in Fig. 3.1a have the

following values:

R1 ¼ 470U; R2 ¼ 1200U; R3 ¼ 1600U; R4 ¼ 330U; R5 ¼ 180U:

If the instrument measuring the output voltage across AB has a resistance of

10,000U, what is the measurement error caused by the loading effect of this

instrument?