2015 - JAMB Physics Past Questions and Answers - page 6

f α (MM ÷g²)

F(GMM ÷ r²) [G – gravitational constant]

GMM = Fr²

G = F0² ÷ MM = m × aπr² ÷ MM (f = ma)

= (m × m5^-2 × r²) ÷ MM

= (Kg.m5² × m²) ÷ Kg.Kg

=1 ÷ kg.m³.5²

The dimension mathematically representation have a quantities of M, L AND T

M (Mass) = kg, L (Length) = M, T (Time) second

G = kg^-1 m².5²(Using dimension rule)

M^-1.L³.T^-2

∴ The universal gravitational constant (G) =( M­^{–1}L^3 T^{–2} )

A good electric cell should proses the following

1. A long life of an electric cell,
   

   
   

2. A minimum of polarization effect
   

   
   

3. A cheap and safe electrolytes
   

   
   

Except D cost and dangerous of the electric cell

V_r.m.s = V₀ ÷ V₂, where V_r.m.s rep. to as voltage root –square mean, v = peak voltage

V_r.m.s = 200volt, v = ?

200 = V₀ ÷ V₂

V₀ = 200_v2

= 200 × 1.414

= 282.8 volts V0 = b &approx.; 283 volts

Convection take place commonly in liquids (water) and slightly in gasses

The regular arrangement of atoms in a crystalline materials is called LATTICES

Diffusion: The movement of water vapors from regions of low concentration toward regions of high concentration

Surface tension: is a force transmitted through a sting or object surface tension = force (N) ÷ Area m2(Nm−2)

The total energy at any point combination of the PE and KE

i.e. T_Energy = PE + K.E

= mgh + ½ mr₂

= ½ m (gh + v² )

= ½ m (v² + gh)

∴ T_Energy = ½ m (V² + gh)

∴ Total energy at the height (hm) = PE + KE

The sum of P.E and KE at any point is always constant .

Sclerotic coat (sclera) is the tough outer coat of the eye that coves the eyeball (ii) sclerotic coat is modified in front of the eye to from a transparent and horny window

Temperature gradient(Tg) = DT ÷ L = T2 – T1 ÷ L

i.e– it is the ratio of an increment in temperature to the length

Hence, Temperature gradient (Tg) has defined direction alongside with magnitude

And it is a vector gratuity

Mass, work & Time are scalar quantity

Efficiency of a transformer = (power developed in the secondary coil ÷ power supplied to the primary coil) × 100%