nabteb 2017/2018 physics practical question and answer solution is now available

number of oscillation =20
height (h)=1.0m
Table of oscillation

S/n; 1,2,3,4,5
y(cm);10.00,20.00,30.00,40.00,50.00
t(s);38.00,35.80,33.60,31.20,28.40
T=t/s(s);1.90,1.79,1.68,1.56,1.42
T^2(s);3.62,3.22,2.82,2.42,2.01

1aiv.
Slope = |> y/ |>T^2=62-10/1.5-3.6=52/-2.1
=-24.76cm/s^2
Intercept I on the vertical axis = 88cm or 0.88m

1av.
precaution
-i avoided error due to parallax when reading the stopwatch and metre rule
-i ensured that the bob was displaced through the small angle to avoid conical oscilation

1ci.
period: this is the time taken or period to complete one oscillation or to and fro movement

frequency :- this is the number of cycle or oscillation to complete in one second

1bi.
-the shape of the earth (spherical)
-distance of the object from its centre

1bii.
diameter =2.4m, r=1.2m, v=8m/s , v=wr
w=v/r =8/1.2 =6.67rads^-1

standard resistor = 1.0 ohm
table of observation
S/N;1,2,3,4,5
I(A);;0.4,0.6,0.8,1.0,1.20
V(v);0.40,0.60,0.80,1.00,1.20
I^1(A^-);2.50,1.67,1.25,1.00,0.83
V^-(V^-);2.50,1.67,1.25,1.00,0.83

3av.
slope, S= |> I^-1/ |> V^-= 3.0-0.5/3.0-0.5=2.5/2.5
=1.0V/A

3avi
from S = |> I^-1 / |>V^-1
1.0= |> I^-1 / |>V^-1 = |> V / |> I
1.0=V/0.75
V=0.75V

3avii.
Precautions:
– i ensured tight connection of connecting wires
-i ensured that the key was opened ,to avoid the runnng down of the battery

3bi.
internal resistance (r); this is the opposition of current flow through the electrolytic cell

3bii.
-heating effect
-chemical effect

heating effect is used in electric cooker for cooking .
3biii.
V=IR ,R=6ohm , v=9v , E=?
I=E/R+r
V/R=E/R+r
9/6=E/6+I
6E=9*7
E=63/6=10.5V
EMF of the cell = 10.5v