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MODUL • Fizik TINGKATAN 5

Latihan / Exercise

1 Rajah menunjukkan bentuk gelombang yang 2 Rajah menunjukkan bentuk gelombang dihasilkan pada
terhasil daripada bekalan kuasa arus ulang-alik skrin O.S.K di radar stesen lapangan terbang. Titik X
yang disambungkan kepada input-Y pada O.S.K. dan Y menunjukkan masa penghantaran isyarat ke kapal
[Gandaan-Y disetkan = 20 V cm dan kawalan dasar masa KBAT terbang dan masa penerimaan pantulan isyarat melalui
–1
= 5 ms cm ] radar tersebut.
-1
The diagram shows a waveform obtained from an a.c. power [Kawalan dasar masa pada O.S.K. = 50 ms cm ]
–1
supply connected to Y-input of a C.R.O. The diagram shows a waveform obtained on the screen of
[Y-gain setting = 20 V cm and time-base control setting = a C.R.O. at an airport radar station. The points X and Y
–1
5 ms cm ] indicate the time of transmission to an aeroplane and the time
–1
of receiving the reflected signals by the radar station.
[Time-base control setting of the C.R.O. = 50 ms cm ]
–1
Y
X

Tentukan, / Determine, 8 cm
(a) tempoh isyarat yang ditunjukkan Hitung
the period of the signal Calculate
(b) frekuensi isyarat (a) masa isyarat radar dari X ke Y.
the frequency of the signal the time travels of the radar from X to Y.
(c) beza keupayaan puncak ke puncak (b) jarak antara stesen radar dan kapal terbang.
the peak to peak voltage [Halaju cahaya = 3 × 10 m s ]
8
–1
(d) beza keupayaan voltan puncak the distance between the radar station and the
the peak voltage aeroplane.
8
–1
Penyelesaian / Solution [Speed of light = 3 × 10 m s ]
Penyelesaian / Solution
(a) Ketetapan kawalan dasar-masa O.S.K. UNIT 4
Time-base control setting of the C.R.O.
UNIT 4
8 cm = 50 ms cm –1

d = 14 cm Masa penghantaran isyarat radar,
Time travels of the radar,
T = 50 ms cm × 8 cm = 400 ms
–1
(a) Ketetapan kawalan dasar masa = 0.4 s
Time-base control setting = 5 ms cm –1
Tempoh / Period, T = 5 ms cm × 14 cm (b) Halaju cahaya = 3 × 10 m s –1
–1
8
= 70 ms Speed of light = 3 × 10 m s –1
8
= 7.0 × 10 s Menggunakan formula, 2D = vt
–2
1 Using formula, 2D = vt
(b) Frekuensi / Frequency, f = T Jarak antara stesen radar dan kapal terbang
1 Distance between the radar station and the aeroplane,
= 7.0 × 10 s vy
–2
= 14.29 Hz D = 2
(c) Ketetapan gandaan-Y / Y-gain setting = 20 V cm = (3 × 10 m s ) × (0.4 s)
–1
–1
8
Voltan puncak ke puncak 2
7
Peak to peak voltage, V = 20 V cm × 8 cm = 6.0 × 10 m
–1
pp
= 160 V
(d) V = Vpp
2
p
160 V
= 2
= 80 V
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