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

= (\frca{2}{6}) × 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