2018 waec physics practical

1)
Tabulate
S/n 1,2,3,4,5
L(cm) 90.00,80.00,70.00,60.00,50.00
T(s) 38.30,35.40,33.40,29.60,27.50
T=t/20(s) 1.92,1.77,1.67,1.48,1.38
sqrL(cm^1/2) 9.49,8.94,8.37,7.75,7.07
1vii)

1

1ix)
slope (s) = D vertical/D horizontal
= 1.90-155/9.49-775
=0.35/1.75
s=0.201
1x)
g=4^2/s^2
=4*(3.142)^2/(0.201)^2
=977.4cm1s^2
1xii)
-precautions-
Take Any Two
i)I avoided conical oscillation
ii)I avoided drought
iii)I avoided parallax error in taking reading from the
metre rule
iv)I avoided zero error in taking reading from the stop
watch
2a)

-Observation-

part of the C dissolves,colourless filtrate salt

-Inference-

C is a mixture of soluble salt

2bi)

-observation-

white precipitate formed

-Inference-

Cl is present

2bii)

-Observation-

precipitate dissolves

-Inference-

Cl confirmed

2biii)

-Observation-

colourless gas evolved with characteristic choking smell,

turns litimus paper blue

-Inference-

Gas is NH3

2c)

-Observation-

Residue dissolves liberating a colourless gas which turns

lime water milky

-Inference-

gas is CO2

CO^2-3 present

======================
(3a)
TABULATE:
x(cm):10,20,30,40,50,60
V(v):0.65,0.75,1.00,1.20,1.45,1.55
I(A):0.20,0.30,0.35,0.40,0.45,0.55
LogV(v):-0.187,-0.125,0.000,0.079,0.161,0.190
LogI(ohm):-0.699,-0.523,-0.456,-0.396,-0.391,-0.360
SLOPE(s):=( LogI2-LOgI1)/(LogV2-LogV1)
=-0.2-(-0.7)/0.3-(-0.2)
=0.5/0.5
=1AV^-1
(3axi)
(i) I ensured neat and tight terminals
(ii) I opened the key when reading was taken
(3bi)
(i)The brightness of the bulb increases
(ii) The voltage and current through the bulb increases
(3bii)
(i) diode
(ii) transistor.....
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