# 2018 NECO GCE PHYSICS PRACTICAL ANSWER

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243  Thursday 15th Nov.
Physics Paper I (Alternative to Practical) – 2.00 pm – 4.45 pm

(NUMBER 1)

(1vii)
(PICK TWO)
(i)I ensured mass did not tourch/rest on the table
(ii)I avoided error due to parallax on metre rule
(iii)I noted zero error on metre rule
(iv)I avoided draught

(1bi)
The principal of moments state that if a body is in equilibrium,then the sum of the clockwise moments about any point on the body is equal to the sum of the anticlockwise moments about the same point

(1bii)

Clockwise moment =Anti clockwise moment

10×5 = RB × 7

RB= 10×5/7
RB=50/7
RB=7.14
RA + RB=10
RA+7.14 =10
RA=10 – 7.14 =2.86N

(3a)
In a tabular form
Under S/N
1, 2, 3, 4, 5, 6

Under R(ohms)
5.0, 10.0, 15.0, 20.0, 25.0, 30.0

Under X(cm)
33.00, 49.50, 60.00, 67.00, 71.00, 74.50

Under K = 100 -X(cm)
67.00, 50.50, 40.00, 33.00, 29.00, 25.50

Under Y = x/k
0.4925, 0.9802, 1.5000, 2.0303, 2.4483, 2.9216

(3avi)
DRAW THE GRAPH

(3avii)
Slope
R2 – R1/y2 -y1
= 20 – 5/2.0 – 0.5
= 15/1.5
=10.0 ohms

(3aviii)
(i) I must use a freshly charged accumulator.
(ii) I must take proper readings through my resistance box and potentiometer to avoid error due to parallax

(3bi)
Lost volt is the voltage lost due to the internal resistance of a cell. It is measured in volts.

(3bii)
E = I(R+r)
4 = I(2+0.5)
4 = 2.5I
I = 4/2.5
= 1.6A keep refreshing the page