Jamb

Physics 2020 (Jamb) General Questions

Physics 2020 (Jamb) General Questions

Physics 2020 (Jamb) General Questions
Physics 2020 (Jamb) General Questions

A man walks 1km due east and then 1 km due north His displacement
√2km N 45°E
1km N 30°E
1km N 15°E
√2km N 60°E
The density of 400cm of palm oil was 0.9gcm-3 before frying. If the density of the oil was 0.6gm-3 after frying, assuming no loss of oil due to spilling, its new volume was?
1360cm3
600cm3
240cm3
8000m3
Which of the following is true of an electrical charge?
Positive charge means deficit electrons
Negative charge means excess of electrons
electric current means movement of electrons
All of the above
Natural radioactivity consists of the emission of
α- particles and β-rays
α- particles and X-rays
α- particles, β – rays and g-rays
γ- rays and X-rays
Which of the following does NOT describe the Image formed by a plane minor?
Erect
Laterally inverted
Same distance from mirror as object
Magnified
What is the resultant resistance of the circuit in the image shown?

11Ω

3.6Ω
Which of the following best describes the energy changes which take place when a steam engine drives a generator which lights a lamp?
heat —-> Light—-> Sound —-> Kinetic
Kinetic —-> Light —-> Heat —-> Electricity
heat —-> Kinetic —-> Electricity —-> Heat and Light
electricity —-> Kinetic —-> Heat —-> Light
Cathode rays are
High-energy electromagnetic waves
protons
neutrons
streams of electrons
A narrow beam of white light can be split up into different Colours by a glass prism. The correct explanation is that
white light Is an electromagnetic wave
the prism has all the colours of the white light
different colours of white light travel with different speeds in glass
white light has undergone total Internal reflection in the prism
The diagram shown represents a block-and-tackle pulley system on which an effort of W Newtons supports a load of 120.0N. If the efficiency of the machine is 40, then the value of W is?
28.0
48.0N
233.0N
50.0N
What type of reaction is represented by the following scheme?
12X + 12Y —–> 32Z + 10n + energy
fusion reaction
fission reaction
Chain reaction
radioactive decay
The amount of heat needed to raise the temperature of 10kg of Copper by 1K is its
specific heat capacity
latent heat
heat capacity
internal energy
The electrochemical equivalent of silver is 0.0012g/C. If 36.0g of silver is to be deposited by electrolysis on a surface by passing a steady current for 5mins, the current must be?
6000A
100A
10A
1A
Shadows and eclipses result from the
refraction of light
reflection of light
defraction of light
rectilinear propagation of light
Which of the following obeys Ohm’s law?
all metals
diode only
all electrolytes
glass
Which of the following statements are TRUE of isotopes?
I. Isotopes of an element have the same chemical properties because they have the same number of electrons
II. Isotopes of elements are normally separated using physical properties
III. Isotopes of an element have the same number of protons in their nuclei
I and II only
I and III only
II and III only
I, II and III
In the diagram given the hanging mass m2 is adjusted until m1 is on the verge of sliding. The coefficient of static
m1m2
m1g⁄m2
m2m1
m2g⁄m1
Which of the following may be used to explain a mirage?
I. Layers of air near the road surface have varying refractive indices in hot weather
II. Road surfaces sometimes become good reflectors in hot weather
III. Light from the sky can be reflected upwards after coming close to the road surface.
I and III only
II and III only
II only
I, II and III
In the diagram given if the atmospheric pressure is 760mm, the pressure in the chamber G Is
660mm
890mm
690mm
860mm
Which of the following has the lowest internal resistance when new?
Leclanche cell
Daniell cell
Torch battery
Accumulator
The pitch of an acoustic device can be increased by
decreasing the loudness
increasing the intensity
increasing the frequency
decreasing the intensity
One of the features of the fission process is that
it leads to chain reaction
its products are not radioactive
neutrons are not released
the of the masses of the reactants equals the sum of the masses of the products
The linear expansivity of brass is 2 x 10-5C-1. If the volume of a piece of brass is 15.00cm at 0°C, what is the volume at 100°C
16.03cm3
15.09cm3
16.00cm3
15.03cm3
A lead bullet of mass 0.05 kg is fired with a velocity of 200 ms into a lead block of mass 0.95 kg. Given that the lead block can move freely. the final kinetic energy after impact is
150J
100J
50J
200J
In a series R-L-C circuit at resonance, the voltages across the resistor and the inductor are 30V and 40V respectively. What is the voltage across the capacitor?
30V
70V
50V
40V
If the fraction of the atoms of a radioactive material left after 120years is 164, what is the half-life of the material?
20 years
10 years
2 years
24 years
In the diagram shown, which of the simple pendulum will resonate with P when set into oscillation?
U
T
R and T
Q and R
The time rate of loss of heat by a body is proportional to the
temperature of its surroundings
temperature of the body
difference in temperature between the body and its surroundings
ratio of the temperature of the body to that of its surroundings
A positively charged rod X is brought near an uncharged metal sphere Y and is then touched by a finger with X still in place. When the finger is removed, the result is that Y has
no charge and a zero potential
a positive charge and a zero potential
a negative charge and a positive potential
a negative charge and a negative potential
Electrical appliances in homes are normally earthed so that
a person touching the appliances is safe from electric shock
both the a.c. and d.c. sources can be used
the appliances are maintained at a higher pd than the earth
the appliances are maintained at a lower pd than the earth
The process whereby a liquid turns spontaneously into vapour is called
regelation
evaporation
boiling
sublimation
Which of the following diagrams represents correctly an n-p-n transistor?
The differences observed in solids, liquids and gases may be accounted for by
their relative masses
their melting points
the spacing and forces acting between the molecules
the different molecules in each of them
Convex mirrors are used as driving mirrors because images formed are
erect, Virtual and diminished
erect, real and diminished
erect, virtual and magnified
inverted, virtual and diminished
Musical instruments playing the same note can be distinguished from one another owing to the difference in their
quality
pitch
intensity
loudness
In the diagram shown, If the south-poles of two magnets stroke a steel bar, the polarities at T and V will respectively be
north and south
south and south
north and north
south and north
In homes, electrical appliances and lamps are connected in parallel because
less current will be used
less voltage will be used
parallel connection does not heat up the wires
series connection uses high voltage
An object moves in a circular path of radius 0.5m with a speed of 1ms-1. What is its angular velocity?
8rads-1
4rads-1
1rads-1
2rads-1
What effort will a machine of efficiency 90% apply to a load of 180N if its efforts arm is twice as long as its load arm?
100N
90N
80N
120N
Calculate the effective capacitance of the circuit in the diagram given
4μf
3μf
2μf
1μf
 
 

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