JAMB UTME - Physics - 2007 | Green Bridge CBT

Question 1 Report

A charge 50 µc has electric field strength of 360 NC-1 at a certain point. The electric field strength due to another charge 120 µc kept at the same distance apart and in the same medium is?

864 NC-1

150 NC-1

144 NC-1

18 NC-1

Answer Details

E =

\frac{F}{q}

and Q1 = 50μF, E1 = 360μF, E2 = ?, Q2 = 120μF
Using E =

\frac{F}{q}

.
So we have F = Q

\times

E
F = 50

\times

10

^{- 6}

\times

360 = 0.018N
When E2 = F/q

\frac{0.018}{120 \times 10^{- 6}}

= 150NC

^{- 1}

Read lesson note on Electric Field (WAEC)

Read lesson note on Electromagnetic Field (Part 2) (WAEC)

Electric Field

Electromagnetic Field (Part 2)

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Question 2 Report

Two long parallel wires X and Y carry currents 3A and 5A each. if the force experienced by unit length is 5 x 10-5N. the force per unit length experienced by wire Y is

3 x 10-5

3 x 10-6

5 x 105

5 x 10-5

Electrostatics

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Question 3 Report

A blacksmith heated a metal whose cubic expansivity is 6.3 x 10-6K-1. The areal expansivity is

2.0 x 10-6K-1

2.1 x 10-6K-1

4.2 x 10-6K-1

6.3 x 10-6K-1

Temperature And Its Measurement

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Question 4 Report

The energy E of a photon and it's wavelength are related by Eλ = X. the numerical value of X is?
[h = 6.63 x 10-34js, c = 3 x 108 ms-1]

6.6 X 10-28

1.99 X 10-27

6.60 x 10-26

1.99 x 10-25

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Question 5 Report

I. Use a liquid with a high melting point.

II. use a liquid of high volume expansivity.

III. use a capillary tube of large diameter.

Which of the above best describes how the sensitivity of a liquid-in-glass thermometer can be enhanced?

I only

II. only

I and II only

II and III only

Answer Details

The question is asking how the sensitivity of a liquid-in-glass thermometer can be enhanced. The three options provided are: (I) use a liquid with a high melting point, (II) use a liquid of high volume expansivity, and (III) use a capillary tube of large diameter. Option I alone cannot enhance the sensitivity of the thermometer. The melting point of a liquid only affects the upper range of temperatures that the thermometer can measure, but it has no effect on the sensitivity or the precision of the measurements. Therefore, option I is not the correct answer. Option II can enhance the sensitivity of the thermometer. The volume expansivity of a liquid refers to how much the volume of the liquid changes with temperature. A liquid with high volume expansivity will change its volume more for a given change in temperature, resulting in a larger change in the length of the column in the thermometer. This means that the thermometer will be more sensitive to temperature changes. Therefore, option II is a correct answer. Option III alone cannot enhance the sensitivity of the thermometer. The diameter of the capillary tube only affects the rate at which the thermometer responds to temperature changes, but it has no effect on the sensitivity or the precision of the measurements. Therefore, option III is not the correct answer. Therefore, the correct answer is option II only, which is "II. use a liquid of high volume expansivity."

Read lesson note on Temperature And Its Measurement (JAMB)

Read lesson note on Pressure (JAMB)

Temperature And Its Measurement

Pressure

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Question 6 Report

The blade of a hoe feel colder to touch in the morning than the wooden handle because the

handle is a better conductor of heat than blade

handle contains stored energy in form of heat

blade is a better conductor of heat than the handle

blade is placed at a lower temperature than the heat

Heat Transfer

Heat Energy

Conduction Of Electricity Through

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Question 7 Report

2 kg of water is heated with a heating coil which draws 3.5 A from a 200 V mains for 2 minutes. what is the increase in temperature of the water?
[specific heat capacity of water = 4200 jkg -1k-1]

30°

25°

15°

10°

Heat Energy

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Question 8 Report

I. Increase the melting point of the liquid.

II. Increase the boiling point of the liquid.

III. Decrease the melting point of the liquid.

IV. Decrease the boiling point of the liquid.

Which of the statement above about the effect on increase in pressure in a liquid are correct?

I and II only

I and III only

II and III only

III and IV only

Change Of State

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Question 9 Report

The phenomenon of light bending round an obstacle is?

diffraction

refraction

reflection

polarization

Reflection Of Light At Plane And Curved Surfaces

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Question 10 Report

In the diagram above , if the magnetic field points into the paper and the force on a current - carrying conductor points upwards, what is the direction of the current?

Upwards

Downwards

Right

Left

Magnets And Magnetic Fields

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Question 11 Report

A string of length 4m is extended by 0.02m when a load of 0.4kg is suspended at its end. What will be the length of the string when the applied force is 15N?

4.05m

4.08m

5.05m

6.08m

Scalars And Vectors

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Question 12 Report

Which of the following gas laws is equivalent to the work done?

Boyle' law

Charles law

Pressure law

van der Waal's law

Answer Details

Mathematically Boyle's law = PV = K
Where P = Pressure
and V = Volume

By definition Pressure = $\frac{F}{A} = \frac{F}{M \times M}$

Again Workdone = force x displacement

therefore $P V = \frac{F}{A} \times V = \frac{F}{M^{2}} \times \frac{M^{3}}{1} P V = \frac{F}{x \times x} \times \frac{x \times x \times x}{1} = F \times x$

= force x displacement

Read lesson note on Gas Laws (JAMB)

Gas Laws

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Question 13 Report

The instantaneous value of the induced e.m.f as a function of time is ε = εo sin ωt where εo is the peak value of the e.m.f. The instantaneous value of the e.m.f., one quarter of the period is

0.00

εo/4

εo/2

εo

Current Electricity

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Question 14 Report

A conductor has a diameter of 1.00 mm and length 2.00m. if the resistance of the material is 0.1Ω, its resistivity is?

2.55 x 105 Ωm

2.55 x 102 Ωm

3.93 x 10-6 Ωm

3.93 x 10-8 Ωm

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Question 15 Report

A radioactive substance has a half-life of 20 days what fraction the original radiation nuclei will remain after 80 days?

(1)/32

(1)/16

(1)/ 8

(1)/4

Wave-particle Paradox

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Question 16 Report

Two spheres of masses 5.0 kg and 10.0 kg are 0.3 m apart. Calculate the force of attraction between them?
[G = 6.67 X 10-11 Nm2 Kg2]

3.50 x 10-10N

3.71 x 10-8 N

3.57 x 10-2N

4.00 x 102N

Gravitational Field

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Question 17 Report

A reservoir 500 m deep is filled with a fluid of density 850 kgm-3. If the atmospheric pressure is 1.05 x 105 Nm-2, the pressure at the bottom of the reservoir is.
[g = 10ms-2]

4.72 x 106 Nm-2

4.36 x 106 Nm-2

4.28 x 106 Nm-2

4.25 x 106 Nm-2

Pressure

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Question 18 Report

A 120 V, 60 W lamp is to be operated on 220 V a.c. the supply mains. calculate the values of non-inductive resistance that would be required to ensure that the lamp is run on current value.

100 Ω

200 Ω

300 Ω

500 Ω

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Question 19 Report

Silicon doped with aluminum and germanium doped with arsenic become?

p- and n- types respectively

n- en p- type respectively

p- type semiconductor

n- type semiconductors

Structure Of The Atom (Nigeria Only)

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Question 20 Report

The unit of moment of a couple can be expressed in?

N m-1

N m-2

N m

N m2

Measurements And Units

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Question 21 Report

I. They should be identical

II. They should originate from the same source.

III. They should be coherent.

IV. They should be monochromatic.

From the statements above, the conditions for two waves to interfere are?

I,II and III only

I, III and IV only

II, III and IV only

I, II, III and IV

Properties Of Waves: Reflection, Refraction, Diffraction

Types Of Waves

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Question 22 Report

A 120V, 60W lamp is to be operated on 220V ac supply mains. calculate the value of non inductive resistance that would be required to ensure that the lamp is run on correct value

100Ω

200Ω

300Ω

500Ω

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Question 23 Report

I. Mass

II. Density

III. Temperature

IV. Nature of substance

Which of the above affect diffusion?

I and II only

I,II and IV only

II, III and IV only

I, II, III and IV

Fundamental And Derived Quantities And Units

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Question 24 Report

.

Three cells each of e.m.f 1.5 V and internal resistance 2.5Ω are connected as shown in the diagram above. Find the net e.m.f and the internal resistance

1.5V, 7.50Ω

1,5V, 0.83Ω

4.5V, 7.50Ω

4.5V, 0.83Ω

View Answer

Question 25 Report

118.8cm2 surface of the copper cathode of a voltameter is to be coated with 10-6m thick copper of density 9 x 103kgm-3. How long will the process run with 10A constant current?

[3.3 x 10-7kgC-1]

5.4 min

10.8 min

15.0 min

20.0 min

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Question 26 Report

If two charged plates are maintained at a potential difference of 3 kv, the work done in taking a charge of 600 µC across the field is?

0.8 J

1.8 J

9.0 J

18.0 J

Electrostatics

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Question 27 Report

A 40KW electric cable was uses to transmit electricity through a resistor of resistance 2.00Ω at 800V. The power loss as internal energy is

4.0 x 102W

5.0 x 102W

4.0 x 103W

5.0 x 103W

Answer Details

In general, Power = IV;

⟹ 40 K W = I V Therefore 40000 = 1 \times 800 ⟹ I = \frac{40000}{800} = 50 A, tune the current through

Resistor = 50A
power loss= I2R = 502 x 2
= 2500 x 2 = 5.0 x 103W

Read lesson note on Electrical Energy And Power (JAMB)

Electrical Energy And Power

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Question 28 Report

The bond that forms a semiconductor is?

covalent

electrovalent

ionic

metallic

Structure Of The Atom (Nigeria Only)

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Question 29 Report

A piece of iron weights 250 N in air and 200 N in a liquid of density 1000 kgm-3. the volume of the iron is?

5.0 x 10-2 ms-2

4.5 x 10--2 ms-3

2.5 x 10-2 ms-8

2.0 x 10-2 ms-3

Temperature And Its Measurement

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Question 30 Report

The production of pure spectrum could easily be achieved using a?

glass prism with a pin

triangular prism with two convex lens

traingular prism only

triangular prism with two concave lenses

Light Energy

Reflection Of Light At Plane And Curved Surfaces

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Question 31 Report

The instrument used by designers to obtain different color pattern is called?

periscop

sextant

episcope

kaleidoscope

Optical Instruments

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Question 32 Report

A clinical thermometer is different from other mercury in glass thermometers owing to

the constriction on its stem

the grade of mercury used in it

its long stem

its wide range of temperatures

Temperature And Its Measurement

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Question 33 Report

When an object is placed between the principal focus and the optical center of a convex lens, it could be used as a?

Simple microscope

refecting lens

compound microscope

projector

Structure Of The Atom (Nigeria Only)

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Question 34 Report

A particle of weight 120N is placed on a plane inclined at 300 to the horizontal. If the plane has an efficiency of 60% to the floor what is the force required to push the weight uniformly up the plane?

50N

100N

175N

210N

Answer Details

Efficiency =

\frac{W (120 N) I N P U T}{W O R K O U T P U T} \times \frac{100}{1}

And for incline plane

V.R = $\frac{1}{S i n θ} = V . R = \frac{1}{S i n 30} = \frac{1}{0.5} = 2 therefore \frac{60}{120} = \frac{M . A}{2} = M . A = \frac{120}{100} = 1.2 but M.A = \frac{l o a d}{e f f o r t} = \frac{120}{E} therefore \frac{120}{E} = 1.2 = E = \frac{120}{1.2} = 100 N$

Therefore Effort up the plane = 100N

Read lesson note on Scalars And Vectors (JAMB)

Read lesson note on Equilibrium Of Forces (WAEC)

Read lesson note on Measurements And Units (JAMB)

Scalars And Vectors

Equilibrium Of Forces

Measurements And Units

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Question 35 Report

A 40 kW electric cable is used to transmit electricity through a resistor of resistance 2.0Ω at 800 V. The power loss as internal energy is?

4.0 x 102W

5.0 x 102W

4.0 x 103W

5.0 x 103W

Heat Energy

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Question 36 Report

The figure above shows 4 forces 3N, 10N, 3√3N and 6N acting on a particle P. The resultant of he four forces is

5N

5√ 3N

10N

10√ 3N

Scalars And Vectors

Equilibrium Of Forces

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Question 37 Report

From the diagram above, the bob of the pendulum has the fastest speed at

X

Y

Z

W

Motion

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Question 38 Report

A boy drags a bag of rice along a smooth horizontal floor with a force of 2N applied at the angle of 60o to the floor. The work done after a distance of 3m is

3 J

4 J

5 J

6 J

Work, Energy And Power

Temperature And Its Measurement

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Question 39 Report

The ratio of the coefficient of linear expansion of two metals ∝1/∝2 is 3:4. If, when heated through the same temperature change, the ratio of the increase in length of the two metals, e1/e2 is 1:2, the ratio of the original lengths l1/l2 is

8/3

3/2

2/3

3/8

Temperature And Its Measurement

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Question 40 Report

In a large telecommunications auditorium, perforated absorbent materials are used to line the ceiling so as to

Increase the reverberation of sound in the hall

increase the amount of echo in the hall

reduce the hight of the ceiling from the floor

reduce the reverberation of sound in the hall

Thermal Expansion

Simple A.C Circuits

Propagation Of Sound Waves

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Question 41 Report

A glass plate 0.9cm thick has a reflective index of 1.50. how long does it take for a pulse of light to pass through the plate?
[c = 3.0 x 8 ms-1]

4.5 x 10-11s

4.5 x 10-10s

4 .5 x 10-12 s

3.0 x 10-10s

Electromagnetic Field (Part 1)

Gravitational Field

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Question 42 Report

A machine has a velocity ratio of 4. if it requires 800 N to overcome a load of 1600 N,what is the efficiency of the machine?

60%

50%

40%

2%

Work, Energy And Power

Simple Machines

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Question 43 Report

A gramophone record takes 5s to reach its constant angular velocity of $4\pi\ \text{rads}^{-1}$ from rest. Find its constant angular acceleration.

0.4

π

rads-2

0.8

π

rads-2

1.3

π

rads-2

20.0

π

rads-2

Newton’s Laws Of Motion

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Question 44 Report

A car of mass 1500 kg goes round a circular curve of radius 50m at a speed of 40 ms-1. The magnitude of the centripetal force on the car is ?

4.8 x 104 N

4.8 x 103 N

1.2 x 103 N

1.2 x 102 N

Equilibrium Of Forces

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Question 45 Report

The difference observed in solids, liquids and gases can be accounted for by

The different molecules in each of them

The spaces and forces acting between the molecules

Thier melting points

Their relative massess

Structure Of Matter And Kinetic Theory

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Question 46 Report

From the diagram above, the inductive reactance and the resistance R are respectively

50Ω and 45Ω

25Ω and 51Ω

20Ω and 50Ω

10Ω and 50Ω

Capacitors

Simple A.C Circuits

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Question 47 Report

The fundamental frequency of a plucked wire under a tension of 400N is 250Hz. When the frequency is changed to 500 Hz at constant length, the tension is

1600N

400N

160N

40N