2017 - JAMB Physics Past Questions and Answers - page 1

s = $\frac{1}{2}$ut + at² is a wrong equation, it should be s = $\frac{1}{2}$ut + at²

Electromagnetic waves do not require any material medium, but sound waves is a mechanical wave that require a material medium

Electric Field Intensity (E) = $\frac{v}{d}$

= $\frac{\text{potential difference}}{\text{distance}}$

= $\frac{6.5v}{35cm}$

= $\frac{6.5}{35\times {10}^{-2}}$

= 18.57NC${}^{-1}$

Soldiers march disorderly while crossing a bridge to prevent resonance because when soldiers march in orderly manner across a bridge, they generate a rhythmic oscillation of wave out. The bridge and at a certain point, would start oscillation to the same rhym as that of the marching steps. This oscillation would reach a maximum peak when the bridge can no longer sustain its own strength and hence collapses. So for this reasons, soldier are ordered to march disorderly while crossing a bridge

Upthrust = change in weight

density = $\frac{\text{mass}}{\text{volume}}$

Mass of liquid displaced = Density of Liquid × Volume;

= 103 × 50 × 10− 6m³

= 0.05kg

(Note that the volume of 50cm3 was converted to m³ by multiplying by 106) i.e 50cm³ = 50 × 10−6m³)

Since mass displaced = 0.05kg

Upthrust = mg = 0.05 × 10

= 0.5N

Cathode rays are produced in a discharge tube under Low pressure and high voltage

For work to be done, distance must be involved because
workdone = force × distance

Latent Energy = mass(m) × specific latent heat (L)
ε = mL

L = ε/m$\frac{E}{m}$

= $\frac{1.13\times 106}{15}$

= 7.53 × 104Jkg${}^{-1}$

Internal resistance determine the maximum current that can be supplied

Efficiency = $\frac{r}{R}$ × 100

= $\text{frca}26$ × 100

= 33.3%

Molecules of liquid are not stationary
Brownian motion is an evidence of particle nature of matter
matter is made up of molecules
The molecules of matter are in constant motion