JAMB UTME - Physics - 2014 | Green Bridge CBT

Pregunta 1 Informe

The quantity of heat needed to raise the temperature of a body by 1K is the body's

Heat capacity

Internal energy

Specific heat capacity

Latent heat of fusion

Quantity Of Heat

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Pregunta 2 Informe

When $ {}^{210}_{82}\mathrm{Pb} $ decays to $ {}^{206}_{80}\mathrm{Pb} $, it emits

two alpha and two beta particles

an alpha particle

one beta particle

one alpha and one beta particle

Structure Of The Atom (Nigeria Only)

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Pregunta 3 Informe

A wheel and an axle is used to raise a load whose weight is 800N when an effort of 250N is applied. If the radii of the wheel and axle are 800mm and 200mm respectively, the efficiency of the machine is

90%

80%

85%

87%

Detalles de la respuesta

VR = 800/200 = 4

E f f i c i e n c y = \frac{M A}{V R} \times \frac{100}{1}

$E f f i c i e n c y = \frac{L}{E} \times \frac{1}{V R} \times \frac{100}{1}$

$E f f i c i e n c y = \frac{800}{250} \times \frac{1}{4} \times \frac{100}{1}$

= 78.74%
= 80%

Lee la nota de la lección en Simple Machines (JAMB)

Simple Machines

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Pregunta 4 Informe

Which gas produces a pink coloured light in a discharge tube?

Mercury

Argon

Air

Neon

Gas Laws

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Pregunta 5 Informe

When a negatively charged rod is brought near the cap of a charged gold leaf electroscope which has positive charges, the leaf

Remains the same

Collapses

Collapses and diverges again

Diverges

Electromagnetic Field (Part 2)

Electrostatics

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Pregunta 6 Informe

A force of 500N1 is applied to a steel wire of cross-sectional area 0.2m2, The tensile stress is

2.5x104Nm-2

1.0x102Nm-2

1.0x103Nm-2

2.5x103Nm-2

Detalles de la respuesta

$S t r e s s = \frac{F o r c e}{A r e a}$
$S t r e s s = \frac{500}{0.2} = 2500$
= 2.5 x 103Nm-3

Lee la nota de la lección en Elasticity (JAMB)

Elasticity

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Pregunta 7 Informe

PHCN measures its electrical energy in

W

KWh

Wh

J

Electric Cells

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Pregunta 8 Informe

The distance between two successive crests of a wave is 15cm and the velocity 300ms-1. Calculate the frequency.

2.0x102Hz

4.5x103Hz

2.0x103Hz

4.5x102Hz

Types Of Waves

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Pregunta 9 Informe

When an atom undergoes a beta decay, the atomic number of the nucleus

Remains unchanged

Decreases by one

Increases by one

Becomes zero

Structure Of The Atom (Nigeria Only)

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Pregunta 10 Informe

An object is placed 10m from a pinhole camera of length 25cm. Calculate the linear magnification.

2.5x102

2.5x10-2

2.5x10-1

2.5x101

Detalles de la respuesta

Linear Magnification = \frac{Length of Camera}{Distance of the Object}

$Linear Magnification = \frac{25}{1000}$

$Linear Magnification = 2.5 \times 10^{- 2}$

Lee la nota de la lección en Electrostatics (JAMB)

Electrostatics

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Pregunta 11 Informe

A boy receives the echo of his clap reflected by a nearby hill 0.8s later. How far is he from the hill?

528m

66m

136m

264m

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Pregunta 12 Informe

An object of mass 20kg is released from a height of 10m above the ground level. The kinetic energy of the object just before it hits the ground is

200J

4000J

2000J

500J

Detalles de la respuesta

The kinetic energy of the object just before it hits the ground is 2000J. We can use the principle of conservation of energy to solve this problem. When the object is released from a height of 10m above the ground level, it has gravitational potential energy which is given by: PE = mgh where: m is the mass of the object g is the acceleration due to gravity h is the height of the object above the ground level Substituting the given values, we get: PE = (20 kg)(9.8 m/s^2)(10 m) = 1960 J As the object falls towards the ground, its potential energy is converted into kinetic energy. At the point just before it hits the ground, all of its potential energy will have been converted into kinetic energy. The kinetic energy is given by: KE = 1/2 mv^2 where: m is the mass of the object v is the velocity of the object To find the velocity of the object just before it hits the ground, we can use the principle of conservation of energy again. The total energy of the system (object + Earth) is conserved, so the potential energy at the top of the fall is equal to the sum of the kinetic and potential energies just before impact. Therefore, we can write: PE at the top = KE just before impact + PE just before impact We know that the PE at the top is equal to 1960 J, and the PE just before impact is zero (since the object is at ground level). Therefore: 1960 J = 1/2 (20 kg) v^2 Solving for v, we get: v = √(2(1960 J)/(20 kg)) = 20 m/s Substituting the value of v into the equation for kinetic energy, we get: KE = 1/2 (20 kg) (20 m/s)^2 = 2000 J Therefore, the kinetic energy of the object just before it hits the ground is 2000 J.

Lee la nota de la lección en Newton’s Laws Of Motion (WAEC)

Lee la nota de la lección en Work, Energy And Power (WAEC)

Newton’s Laws Of Motion

Work, Energy And Power

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Pregunta 13 Informe

The equation PaVbTc= constant reduces to Charles Law if

a=1, b=1and c=0

a=1, b=0 and c=-1

a=0, b=1 and c=1

a=0, b=1 and c=-1

Temperature And Its Measurement

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Pregunta 14 Informe

A glass bottle of initial volume 2 x 104 cm3 is heated from 20oC to 50oC. If the linear expansivity of glass is 9 x 106K-1, the volume of the bottle at 50oC is

20016.2cm3

20005.4cm3

20008.1cm3

20013.5cm3

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Pregunta 15 Informe

When a telescope is in normal use, the final image is at

Infinity

The focus

The radius of curvature

The near point

Optical Instruments

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Pregunta 16 Informe

Which type of motion do the wheels of a moving car undergo?

Vibratory and translational motion

Random and translational motion

Rotational mand oscillatory motion

Translational and rotational motion

Simple Harmonic Motion

Motion

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Pregunta 17 Informe

What is the least possible error encountered when taking measurement with a meter rule?

0.1mm

1.0mm

0.5mm

0.2mm

Measurements And Units

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Pregunta 18 Informe

The melting point of a substance is equivalent to its

Vapour Pressure

Solidification Temperature

Liquidification Temperature

Solidification Pressures

Change Of State

Vapours

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Pregunta 19 Informe

A machine whose efficiency is 75% is used to lift a load of 1000N. Calculate the effort put in to the machine if it has a Velocity ratio of 4.

343.32N

233.33N

333.33N

334.33N

Detalles de la respuesta

\frac{M A}{V R} \times \frac{100}{1} = e f f i c i e n c y

$\frac{L}{E} \frac{1}{V R} \times \frac{100}{1} = 75$

$\frac{1000}{E} \frac{1}{4} \times \frac{100}{1} = 75$

$E = \frac{250 \times 100}{75}$

E = 333.3N

Lee la nota de la lección en Simple Machines (JAMB)

Simple Machines

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Pregunta 20 Informe

A circuit has a resistance of 200?. The resistance of the circuit can be reduced to 120? when

A 300Ω resistor is connected to it in parallel

An 80Ω resistor is conneceted to it in series

A 150Ω resistor is connected to it in parallel

A 240Ω resistor is connected to it in series

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Pregunta 21 Informe

In a common emitter configuration, the output voltage is through the

Resistor

Base

Collector

Emitter

Electrostatics

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Pregunta 22 Informe

A quantity which requires magnitude and direction to be specified is

Temperature

Distance

Displacement

Mass

Scalars And Vectors

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Pregunta 23 Informe

What happens when three coplanar non-parallel forces are in equilibrium?

Their lines of action are parallel.

They are represented in magnitude only

They are represented in direction only

Their lines of action meet at a point

Scalars And Vectors

Simple Harmonic Motion

Equilibrium Of Forces

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Pregunta 24 Informe

The maximum power transfer occur in a cell when the external resistance is

Twice the internal resistance of the cell

The same as the internal resistance of the cell

Greater than the internal resistance of the cell

Less than the internal resistance of the cell

Current Electricity

Electric Cells

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Pregunta 25 Informe

If a metal wire 4m long and cross-sectional area 0.8 mm2 has a resistance of 60, find the resistivity of the wire

5.3x10-7

3.0x10-5

1.2x10-6

3.2x10-6

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Pregunta 26 Informe

The small droplets of water that form on the grass in the early hours of the morning is

Fog

Haul

Mist

Dew

Fluid At Rest

Temperature And Its Measurement

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Pregunta 27 Informe

Calculate the mass of the copper deposited during electrolysis when a current of 4A passes through a copper salt for 2 hours. [Ece of Copper z=3.3x10-7kgC-1]

2.9x105kg

9.5x10-7kg

9.5x10-3kg

2.9x104kg

Heat Energy

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Pregunta 28 Informe

I Electrical potential, II Torque, III Kinetic Energy, IV Momentum. Which of the quantities listed are vectors?

II and IV

I and II

I and III

II and III

Scalars And Vectors

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Pregunta 29 Informe

What type of reaction is represented by the equation $ {}^{2}_{1}X + {}^{2}_{1}X \rightarrow {}^{3}_{2}Y + {}^{1}_{0}n + \text{Energy} $

Ionization

Fusion

Fission

Chain

Structure Of The Atom (Nigeria Only)

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Pregunta 30 Informe

One of the conditions necessary for an object to be in equilibrium when acted upon by a number of parallel forces is that the vector sum of the forces is

Average

Zero

Negative

Positive

Equilibrium Of Forces

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Pregunta 31 Informe

The energy in the nucleus of atoms produce heat which can be used to generate

Kinetic energy

Mechanical energy

Electrical energy

Potential energy

Heat Energy

Induction

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Pregunta 32 Informe

Heat transfer by convection in a liquid is due to the

Latent heat of vaporization of the liquid

Increased vibration of the molecules of the liquid about theit mean position

Variation of density of the liquid

Expansion of the liquid as it is heated

Heat Transfer

Fluid At Rest

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Pregunta 33 Informe

The temperature at which the water vapour present in the air is just sufficient to saturate air is

Boiling point

Ice point

Saturation point

Dew point

Temperature And Its Measurement

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Pregunta 34 Informe

What charge is stored in a 0.1F capacitor when a 10V supply is connected across it?

1C

5C

4C

2C

Capacitors

Electric Cells

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Pregunta 35 Informe

The focal length of a concave mirror is 2.0cm. If an object is placed 8.0cm from it, the image is at

2.7m

2.0m

2.3m

2.5m

Detalles de la respuesta

\frac{1}{U} + \frac{1}{V} = \frac{1}{f}

$\frac{1}{8} + \frac{1}{V} = \frac{1}{2}$

$V = \frac{8}{3}$

$V = 2.7 c m$

Lee la nota de la lección en Structure Of The Nucleus (WAEC)

Structure Of The Nucleus

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Pregunta 36 Informe

What is the best method of demagnetizing a steel bar magnet?

Hammering

Heating it

Rough handling it

Solenoid method

Magnets And Magnetic Fields

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Pregunta 37 Informe

In a compound microscope, the objective and the eye piece focal lengths are

At infinity

Long

Short

he same

Structure Of The Atom (Nigeria Only)

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Pregunta 38 Informe

An object of weight 80kg on earth is taken to a planet where acceleration due to gravity is one-third of its value on earth. The weight of the object on the planet is

48N

12N

27N

36N