1997 - JAMB Physics Past Questions and Answers - page 5
41
The following are the scores of ten students in a test of 20 marks: 15, 16, 17, 13, 16, 8, 5, 16, 19, 17. What is the modal?
A
13
B
15
C
16
D
19
correct option: c
Users' Answers & Comments42
Find the standard deviation of the following data -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5
A
2
B
3
C
√10
D
√11
correct option: c
x = \(\frac{\sum x}{N}\) = \(\frac{0}{11}\)
= 0
\(\begin{array}{c|c} x & (x - x) & (x - x)^2\ \hline -5 & -5 & 25 \ -4 & -4 & 16\-3 & -3 & 9\ -2 & -2 & 4\ -1 & -1 & 1\ 0 & 0 & 0 \1 & 1 & 1\ 2 & 2 & 4 \ 3 & 3 & 9 \ 4 & 4 & 16\ 5 & 5 & 25 \ \hline & & 110\end{array}\)
S.D = \(\sqrt{\frac{\sum(x - x)^2}{\sum f}}\)
= \(\sqrt{\frac{110}{11}}\)
= \(\sqrt{10}\)
Users' Answers & Comments= 0
\(\begin{array}{c|c} x & (x - x) & (x - x)^2\ \hline -5 & -5 & 25 \ -4 & -4 & 16\-3 & -3 & 9\ -2 & -2 & 4\ -1 & -1 & 1\ 0 & 0 & 0 \1 & 1 & 1\ 2 & 2 & 4 \ 3 & 3 & 9 \ 4 & 4 & 16\ 5 & 5 & 25 \ \hline & & 110\end{array}\)
S.D = \(\sqrt{\frac{\sum(x - x)^2}{\sum f}}\)
= \(\sqrt{\frac{110}{11}}\)
= \(\sqrt{10}\)
43
![](https://publicappmediaqa.s3.eu-central-1.amazonaws.com/21279_1.jpg)
A
\( 15^{\circ} \)
B
\( 30^{\circ} \)
C
\( 45^{\circ} \)
D
\( 60^{\circ} \)
correct option: d
Users' Answers & Comments44
![](https://publicappmediaqa.s3.eu-central-1.amazonaws.com/21280_1.jpg)
A
mg sinθ and the normal reaction
B
mg sinθ and the force of friction
C
mg sinθ and the normal reaction
D
mg cosθ and the normal reaction
correct option: b
Users' Answers & Comments45
![](https://publicappmediaqa.s3.eu-central-1.amazonaws.com/21281_1.jpg)
A
T =2√3/3
B
T= 2F
C
T = 5V3F/3
D
T = 5F
correct option: d
Users' Answers & Comments46
![](https://publicappmediaqa.s3.eu-central-1.amazonaws.com/21282_1.jpg)
A
tan θ = coefficient of static friction
B
cos θ = coefficient of dynamic friction
C
sin θ = coefficient of sliding friction
D
sec θ = limiting frictional force
correct option: a
Users' Answers & Comments47
![](https://publicappmediaqa.s3.eu-central-1.amazonaws.com/21283_1.jpg)
A
destructively to produce a wave of larger amplitude
B
destructively to produce a wave of smaller amplitude
C
constructively to produce a wave of larger amplitude
D
constructively to produce a wave of smaller amplitude
correct option: a
Users' Answers & Comments48
![](https://publicappmediaqa.s3.eu-central-1.amazonaws.com/21284_1.jpg)
A
Penumbra and sees a partial eclipse
B
Penumbra and sees a total eclipse
C
umbra and sees a partial eclipse
D
umbra and sees a total eclipse
correct option: a
Users' Answers & Comments49
![](https://publicappmediaqa.s3.eu-central-1.amazonaws.com/21285_1.jpg)
A
\( \theta _3 \)
B
\( \theta _2 \)
C
\( \theta _1 \)
D
\( \theta _4 \)
correct option: c
Users' Answers & Comments