EXERCISE 1_Chapter 1
1. In one practical session, students are required to record 5 sets of reading for the voltage.
The readings are shows in Table 1. Determine between reading no 2 and reading no 4,
which reading are mostly precise, and explain your answer.
Table 1
2.
No of reading
Output voltage
1
10v
2
10.9v
3
10v
4
10.8v
5
10.9v
Figure 2 is shows the circuit for basic dc meter that be used to measure dc voltage. The
main structure of the meter consists of very small and light coil winding, which can
measure a very small voltage in few millivolts. Given internal resistance, Rm=800Ω and
full scale deflection current, Ifsd=4mA. Give the suggestion for circuit modification to
measure large voltage. Derive and calculate the required parameters for circuit
modification if V=5V and draw the modified circuit.
Ifsd
Rm
Figure 2
3.
The voltage across R2 of the system as shown in Figure 3 need to verify by using two
voltmeters with different sensitivity, determine which voltmeter will read more
accurately and give the reasons. Given the voltmeters having sensitivity of 500Ω/V
and 2000Ω/V. Both the meters are used on the 200V range.
R1
18kΩ
R2
23kΩ
250V
+
Voltmeter
-
Figure 3