Page 511 - Canadian BC Science 9

A
D.C. Amperes
B. This ammeter has the positive wire connected to the 500 mA scale. The 5 on the bottom scale is the first digit in 500 mA, so the 5 now represents 500 mA. The needle is pointing to 4.7, so the meter is reporting 470 mA of current.
B
D.C. VOLTS
500 mA 100 mA 10 mA
1 A
5 A 10 A
Instant Practice—Using Circuit Symbols and Electric Meters
1. Sketch the following circuit diagram symbols:
(a) battery
(b) light bulb (c) resistor
(d) open switch (e) ammeter
(f) voltmeter
2. State the colour that is associated with: (a) the positive terminal of a meter
(b) the negative terminal of a meter
3. When you connect a meter to a circuit, to which side of the power source should you always connect the positive terminal of the meter?
4. For which type of meter do you need to disconnect the circuit before connecting the meter to the circuit?
5. A student wishes to use a meter to collect the most accurate measurement without damaging the meter. Describe the correct approach for choosing the appropriate scale.
6. Determine the value of current or voltage indicated by meters A to D in the next column.
C
D
25 10 5 2.5 1
50 100 250 500 1000
25 10 5 2.5 1
50 100 250 500 1000
􏰀􏰁
D.C. VOLTS
􏰀􏰁
D.C. VOLTS
25 10 5 2.5 1
50 100 250 500 1000
􏰀􏰁
D.C. Amperes
500 mA 100 mA 10 mA
1 A
5 A 10 A
.4 1.0 2
.4 1.0 2
.4 1.0 2
.4 1.0 2
.4 1.0 2
1 2.5 5
1 2.5 5
1 2.5 5
1 2.5 5
1 2.5 5
.2 .5 1
.2 .5 1
.2 .5 1
.2 .5 1
.2 .5 1
.8 2.0 4
.8 2.0 4
.8 2.0 4
.8 2.0 4
.8 2.0 4
.6 1.5 3
.6 1.5 3
.6 1.5 3
.6 1.5 3
.6 1.5 3
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
Science Skill 11 • MHR 493