
Thursday 2nd May, 2019
Physics 3 (Practical) (Alternative A) – 09:30 a.m. – 12:15 p.m. (1st Set)
Physics 3 (Practical) (Alternative A) – 12:40 p.m – 3:25p.m. (2nd Set)
History 2 (Essay) – 2:00p.m. – 4:00 p.m. History 1 (Objective) – 4:00 p.m. – 5:00 p.m. =======================================
PHYSICS PRACTICAL ANSWERS
(1aviii)
In a tabular form
Under y(cm)
20.0, 30.0, 40.0, 50.0, 60.0
Under t(s)
36.61, 33.66, 31.32, 28.62, 25.93c
Under T = t/20(s)
1.8305, 1.6830, 1.5660, 1.4310, 1.2965
Under T²(s²)
3.3507, 2.8325, 2.4524, 2.0478, 1.6809
(1ax)
Slope s = ΔT²/Δy
S = 4 - 2.5/0 - 39
S = 1.5/-39
S = -0.0385
Intercept, C = 4.0
(1axi)
SR = c
R = c/s = 4/-0.0385 = -103.9
(1axii)
(i) I ensured that the retort stand was well clamped.
(ii) I avoided error due to parallax when reading the metre rule.
3a)
(i) Emf , F=3.00v
Tabulate
R(π) : 2.0,5.0,10.0,12.0,15.0,20.0
V(v): 0.86,0.62,0.43,0.38,0.32,0.25
V^-1(v^-1): 1.1628,1.6129,2.3256,2.6316,3.1280,4.000
(1bi)
Draw the diagram
(α) K.E is maximum
(β) acceleration is maximum
(1bii)
Period, T = 2π√m/k
Given : weight, W = 120N
Mass = w/g = 120/10 = 12
T = 45
π = 3.142
4 = 2(3.142)√12/k
0.6365 = √12/k
Square both sides
0.405 = 12
K = 12/0.405 = 29.6
(3ix)
Slope (s) =ΔR/Δv^-1
= 17.5-4.25/3.5-1.5
= 13.25/2
= 6.625
Intercept (c) = -5.75
(3x)
S=Ro alpha (please use the alpha sign)
6.625=0.85(alpha)
alpha = 6.625/0.85=7.79
C= -(Ro +β)
-5.75= - (0.85+β)
β= 5.75-0.85
β=4.9
3axi)
(i) I ensured tight connections.
(ii) I avoided error due to parallax when reading the voltmeter.
(3bi)
Vab = 12 - 8 = 4v
Rab = 4×5/4+5 = 20/9ohms
Iab = Vab/Rab = 4/20/9 = 4 ×9/20 = 9/5
=1.8A
Power = I²ab Rab
=1.8² * 20/9
= 7.2watts
(3bii)
Current in line = power/voltage = 3600/240
=15A
Circuit breaker remain closed because current in line is less than 20A
(3x)
(i) I avoided parallax error when taking readings from the voltmeter
(ii) I ensured that the key was opened when reading is not been taking
(3)
CLICK HERE FOR THE IMAGE
(3x)
(i) I avoided parallax error when taking readings from the
voltmeter
(ii) I ensured that the key was opened when reading is not
been taking,,,,





COMPLETED+++++