Page 187 - Physics Form 5 KSSM_Neat

Activity 5.3 Teacher’s demonstration CHAPTER 5

Aim: To study the effects of a magnetic field on cathode rays using a Maltese cross tube Electronics
Apparatus: Maltese cross tube, 6 V power supply, E.H.T. power supply, bar magnet and
connecting wires
Instructions:
KEMENTERIAN PENDIDIKAN MALAYSIA
1. Set up the apparatus as shown in Figure 5.3.

Vacuum
Maltese cross
Cathode Anode
S
1
6 V power
supply Shadow

S
2
Fluorescent
– + screen
E.H.T. power supply

Figure 5.3 Maltese cross tube
2. Turn on switch S of the 6 V power supply. Observe
SCAN ME
1 SCAN ME
the shadows formed on the fluorescent screen. Record Demonstration
your observation. video of a Maltese
3. Turn on switch S and observe the shadow formed on the cross tube
2
fluorescent screen again. https://bit.ly/3bf1SPR
4. Bring the north pole of a magnet to the right side of the
Maltese cross tube and observe changes of the shadow.
Safety Precaution
5. Record all your observations. Safety Precaution
Discussion: • Do not touch any metal part of the
Maltese cross tube while using
1. State your observations of the shadow formed on the the E.H.T. power supply.
fluorescent screen when: • Ensure that the E.H.T. power
(a) switch S is turned on supply is switched off when no
1
(b) switches S and S are turned on observations are being recorded.
1 2
(c) switches S and S are turned on and the north pole of a
1 2
magnet is brought to the side of the Maltese cross tube.
2. Explain your observations when the north pole of Note
a magnet is brought to the right side of the Maltese
cross tube. Ensure that the Maltese cross
tube is properly earthed when the
experiment is running.

LS 5.1.2 177