Two forces each of 4 N act on the opposite sides of a rectangular plate as shown in the diagram above. Calculate the magnitude of g the couple acting on the plate.
A6.4 Nm
B3.2 Nm
C1.6 Nm
D0.8 Nm
E0.0 Nm
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Question 2012
waec1990
A girl whose mass is 55kg stands on a spring - weighing machine inside a lift. When the lift starts to ascend, its acceleration is 2ms1. What will be the reading on the machine? (Take g = ms-2)
A66 kg
B55 kg
C44 kg
D22 kg
E11 kg
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Question 2013
waec1990
The diagram above represents a portion of a micrometer screw 20 gauge. What is its reading?
A3.70mm
B3.67mm
C3.50mm
D3.33mm
E3.17mm
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Question 2014
waec1990
A plane inclined at an angle at 30o to the horizontal has an efficiency of 50%. The force parallel to the plane required to push a load of 120 N uniformly up the plane is
A40√3N
B60N
C120N
D200N
E240N
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Question 2015
waec1990
Which of the following are contact forces? I. Force of tension II. Force of fiction, III. Magnetic force III Force of reaction.
AI,II and III only
BI, II and IV only
CI, III and IV only
DII, III and IV only
El and IV only.
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Question 2016
waec1990
An oscillating pendulum has a velocity of 2ms-1 at the equilibrium position O and velocity at same point P. Using the diagram above, calculate the height of P above O. (Take g = 10ms2)
A5.0m
B2.0m
C0.4m
D0.2m
E0.1m
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Question 2017
waec1990
A particle of mass 2.5 x 10-6kg revolving around the earth has a radial acceleration of 4 X 107 ms-2. What is the centripetal force of the particles?
A6.25 x 10-14N
B1.60 x10-13N
C5.00 x 10N
D1.00x102N
E2.00x1O2N
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Question 2018
waec1990
Which of the following instruments is suitable for making the most accurate measurement of the internal diameter of a test tube?
Ametre rule
BA pair of callipers
CA micrometer screw gauge
DA tape rule
EA set square
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Question 2019
jamb1990
A force of 5N act at a point Y on a rod XYZ as shown in the diagram above, if XY is 2m. What is the moment of the force about point X?
A0Nm
B3Nm
C7Nm
D10Nm
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Question 2020
jamb1990
What is the average velocity of the sprinter whose velocity time graph is as shown above
A85.0ms-1
B17.0ms-1
C8.5ms-1
D1.7ms-1
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Question 2021
jamb1990
Two horizontal forces, 10N and 8N and another force F1 inclined at 30 to the vertical acting as shown in the diagram above, keep the body P in equilibrium, The weight of the body is
A2√3/3N
B√2N
C4√3/3
D2V3N
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Question 2022
jamb1990
What is the reading of the vernier scale above
A1.88cm
B1.80cm
C1.28cm
D1.97cm
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Question 2023
jamb1990
The photocell works on the principle of the
Avoltaic cell
Bemision of electrons by incident radiation
Cemision of protons by incident electrons
Dphotographic plate
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Question 2024
jamb1990
A substance has a half of 3mins. after 6mins. the count rate was observed to be 400. What was its count rate at zero time?
A200
B1200
C1600
D2400
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Question 2025
jamb1990
What precaution should a manufacturer take to ensure that energy loss in a transformer is minimized?
Athe winding of the transformer should be made of high resistance wire
Bthe core should be made of thin sheets of metal
Cno magnetic material should be used to make the core
Dthe flux linking the primary with the secondary coils should be minimum
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Question 2026
jamb1990
The number of neutrons contained in the nucleus \(^{238}_{92}U\) is
A92
B146
C238
D330
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Question 2027
jamb1990
A 0 - 10mA galvanometer with a coil resistance of 30\(\Omega\) can be converted to a 0 - 10A ammeter by using
A0.03\(\Omega\) series resistor
B0.03\(\Omega\) shunt resistor
C9.99\(\Omega\) shunt resistor
D9.99\(\Omega\) series resistor
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Question 2028
jamb1990
A lamp is rated 240V, 60W. The resistance of the filament is
A960\(\Omega\)
B16\(\Omega\)
C15\(\Omega\)
D4\(\Omega\)
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Question 2029
jamb1990
Electrical power is transmitted at a high voltage rather than low voltage because the amount of energy loss is reduced due to
Aheat dissipation
Bproduction of eddy currents
Cexcessive current discharge
Dexcessive voltage distance
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Question 2030
jamb1990
Which of the following is most suitable for protecting the circuit of 2000W electric iron connected to a 250V mains?
