A 100kg box is pushed along a road with force of 500N. If the box moves with a uniform velocity, the coefficient of friction between the box and the road is
A0.4
B1.0
C0.8
D0.5
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Question 1252
jamb2004
In a hydraulic press , a force of 40N is applied on the effort piston of area 0.4m2. If the force exerted on the load piston is 400N, the area of the large piston is
A4m2
B8m2
C2m2
D1m2
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Question 1253
jamb2004
I. Jet propelled aircraft
II. Rocket propulsion
III. The recoil of a gun
IV. A person walking
Which of the above is based on Newton's third law of motion
AI and II only
BI, II, III, and IV only
CI and III only
DI, II and III only
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Question 1254
jamb2004
A machine whose efficiency is 60% has a velocity ratio of 5. If a force of 500N is applied to lift a load P, what is the magnitude of P?
A1500N
B500N
C4166N
D750N
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Question 1255
jamb2004
A body of mass 4kg is acted on by a constant force of 12N for 3 seconds. The kinetic energy gained by the body at the end of the time is
A144J
B162J
C81J
D72J
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Question 1256
jamb2004
If the angle between two vectors P and Q is Oº, the vectors are said to
Aintersect at the angle 45o
Bintersect at the angle 60o
Cbe parallel
Dbe perpendicular
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Question 1257
jamb2004
In the diagram above, the ratio of he electric power dissipated in the 6Ω and the 3Ω resistor respectively is
A2:1
B2:2
C1:3
D1:2
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Question 1258
jamb2004
To protect a material from the influnce of an external magnetic field, the materials should be kept
Asquare steel ring
Btriangular zinc ring
Csoft iron ring
Dloop of copper wire
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Question 1259
jamb2004
The difference between X-rays and gamma rays is that
Ax-rays are more penetrating than gamma rays
Bx-rays are electromagnetic radiations while gamma rays are negatively charged radiation
Cx-rays have higher frequencies than gamma rays
Dx-rays arise from energy changes in the electronic structure of atoms while gamma rays come from the nucleus
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Question 1260
jamb2004
Given three capacitors 0.3μF, 0.5μF and 0.2μF, the joint capacitance when arranged to give minimum capacitance is
A0.1μF
B0.3μF
C1.0μF
D0.5μF
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Question 1261
jamb2004
Electrical appliances at home are normally earthed so that?
Athe appliances are maintained at a lower p.d than the earth
Bboth the a.c and d.c sources can be used
Ca person touching the appliances is safe from electric shock
Dthe appliances are maintained at a higher p.d than the earth
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Question 1262
jamb2004
If 16mA of current flows through a conductor in one second, the number of electron transported per seconds is
[1 electronic charge = 1.6 x 10-19C]
A1.00 x 1020
B2.56 x 10-18
C2.56 x -17
D1.00 x 1017
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Question 1263
jamb2004
The instrument used for securing a large number of similar charges by induction is called
Aelectrophorus
Bcapacitor
Cproof-plane
Delectroscope
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Question 1264
jamb2004
A steady current of 2A flows in a coil of emf 12V for 0.4s. A back emf of 3V was induced during this period. The stored energy in the loop that can be utilized is
A9.6J
B2.4J
C12.0J
D7.2J
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Question 1265
jamb2004
Which of the following is an electrolyte?
AParaffin
BSugar solution
CGrape fruit
DAlcohol
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Question 1266
jamb2004
The energy stored in an inductor of inductance 5mH when a current of 6A flows through it is
A9.0 x 10-3J
B9.0 x 10-2J
C1.4 x 10-2J
D1.8 x 10-3J
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Question 1267
jamb2004
Flourescent tubes produces light by the
Aexcitation of gas molecules
Bconduction of solar energy
Crefraction of light by gas molecules
Dthermal agitation of electron in the tubes
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Question 1268
jamb2004
The binding energy of helium \(^4 _2\) He is [atomic mass of proton = 1.00783U, atomic mass of neutron = 1.00867U]
A4.033U
B2.017U
C0.033U
D0.330U
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Question 1269
jamb2004
In a tuned radio receiver R, L, C series circuit for resonance, the inductive and capacitive reactance XL and XC respectively are related as
AXL = XC
BXL = 1/2XC
CXL = 1/XC
DXL = 2XC
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Question 1270
jamb2004
In a reverse biased junction diode, current flows in by
