Page 150 - Physics Form 5 KSSM_Neat

Activity 4.3

Aim: To study the factors that affect the magnitude of the force acting on a current-carrying
conductor in a magnetic field
Apparatus: Direct current power supply, U-shaped steel yoke, two pairs of Magnadur magnets,
electronic balance and retort stand
KEMENTERIAN PENDIDIKAN MALAYSIA
Materials: Copper wire (s.w.g. 20), crocodile clip and connecting wires
Instructions:
1. Set up the apparatus as shown in Figure 4.5.

D.C. power supply
Note
Retort stand
The interaction between the
South pole of magnetic fields of the current in
magnet the copper wire and the Magnadur
AC + DC –
magnets will produce a catapult
field. The catapult field exerts a
force vertically upwards on the
copper wire. At the same time, the
North pole Magnadur magnets experience
of magnet a reaction force with the same
magnitude but in the opposite
direction. This force acts on the
Copper pan of the electronic balance to
wire give a reading that represents the
Connecting magnitude of the force. Hence, a
Steel yoke wire larger force will produce a larger
reading of the electronic balance.
Electronic balance
Figure 4.5
2. Adjust the output to 1 V on the D.C. power supply. Reset
the reading of the electronic balance to zero.
SCAN ME
3. Turn on the power supply and record the reading of the SCAN ME
electronic balance. Then, turn off the power supply. Video of force
measurement
4. Repeat steps 2 and 3 with output voltage 2 V. Record your
results in Table 4.1. http://bit.ly/3lf051t
5. Add another pair of Magnadur magnets on the steel yoke
and repeat steps 2 and 3. Record your results in Table 4.1.
Results:
Table 4.1 Note
Number of Reading of electronic
Voltage / V The north pole and the south
magnets balance / g pole of the Magnadur magnet
can be determined by bringing a
1 One pair
bar magnet near the Magnadur
magnet. Remember that like poles
2 One pair
repel while opposite poles attract.
1 Two pairs

140 LS 4.1.3