JAMB UTME - Physics - 1989 | Green Bridge CBT

Question 1 Report

The magnitude of the resultant of two mutually perpendicular forces, F1 and F2 is 13N, if the magnitude of F1 is 5N, what is the magnitude of F2?

2.6N

6.0N

12.0N

18.0N

Scalars And Vectors

Equilibrium Of Forces

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Question 2 Report

The figure above shows a uniform circular object, center R and diameter PS. A circular section 6 and Diameter PR is cut from it. if PQRS is a straight line, where is center of gravity of the figure

Q

R

A point between P and R

A point between R and S

Gravitational Field

Motion

Measurements And Units

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Question 3 Report

Light of wavelength 5000 x 10-8cm travels in free space with a velocity of 3 x 108ms-1. What is its wavelength in glass of refractive index 1.5?

3333 x 10-8cm

5000 x 10-8cm

6666 x10-8cm

750010-8cm

Light Energy

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Question 4 Report

In the figure above W1 = 200g, and W2 =450g . Calculate the extension of the spring per unit load? [g = 10ms-2]

6.0 x 10-5mN-1

2.5 x 10-4mN-1

6.0 x 10 -3mN-1

2.5 x 10 -2mN-1

Elasticity

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Question 5 Report

Eight alpha decays and six beta decays are necessary before an atom of $ {}^{238}_{92}\mathrm{U} $ achieves stability. The final product in the chain has an atomic number of

70

78

82

90

Answer Details

U

\to

8(

_{2}^{4} H e

) + 6(

_{- 1}^{0} e

) +

_{a}^{b} X

92 = (8 X 2) + (6 X -1) + a

a = 82

Read lesson note on Structure Of The Atom (Nigeria Only) (WAEC)

Structure Of The Atom (Nigeria Only)

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Question 6 Report

When a yellow card is observed through a blue glass, the card would appear.

black

green

red

white

Structure Of The Nucleus

Structure Of The Atom (Nigeria Only)

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Question 7 Report

Three resistors, with substances $250\Omega$, $500\Omega$ and $1k\Omega$ are connected in series. A 6V battery is connected to either end of the combination. Calculate the pot3ential difference between the end of the $250\Omega$ resistor.

0.20V

0.86V

1.71V

3.43V

Answer Details

Using voltage - divider method

v1 = $\frac{(R_{1})}{R_{T}}$ VT

= $\frac{250}{1750}$ x $\frac{6}{1}$

= 0.86V

Read lesson note on Current Electricity (JAMB)

Current Electricity

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Question 8 Report

The function of a 5-A fuse included in a circuit supplying a household refrigerator with power is to keep the

Temperature of the refrigerator low and constant

keep current supplied to the refrigerator below 5A

Voltage supply constant

Current supplies to the refrigeration

Current Electricity

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Question 9 Report

In a sound wave in air, the adjacent rarefactions and compressions are separated by a distance of 17cm. If the velocity of the sound wave is 340ms-1. Determine the frequency

10Hz

20Hz

1000Hz

5780Hz

Answer Details

λ

= 2L

2 x 17 = 34cm

F = $\frac{V}{λ}$

= $\frac{340}{34 \times 10^{- 2}}$

= 1000Hz

Read lesson note on Current Electricity (JAMB)

Current Electricity

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Question 10 Report

Which of the following pairs is NOT part of the electromagnetic spectrum? i. Radio waves. ii. Beta rays. iii. Gamma rays. iv. Alpha rays

i and ii

iii and iv

i and iii

ii and iv

Electromagnetic Waves: Types Of Radiation In Electromagnetic Spectrum

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Question 11 Report

The total power drawn from the cell in the circuit above is

12W

24W

32W

40W

Electrical Energy And Power

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Question 12 Report

A far sighted person cannot see objects that are less than 100cm away. If this person wants to read a book at 25cm, what type and focal length of lens does he need?

convex, 20cm

concave, 20cm

convex, 33cm

concave, 33cm

Electrostatics

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Question 13 Report

An ammeter of resistance $1.0\,\Omega$ has a full-scale deflection of 50mA. Determine the resultant full-scale deflection of the meter when a shunt of $0.0111\,\Omega$ is connected across its terminals.

400mA

450mA

500mA

550mA

Answer Details

V = 0.1 x 50 x 10-3 = 5 x 10-3volts

RT = $\frac{0.1 \times 0.0111}{0.1 + 0.0111}$

= 9.99 x 10-3 $Ω$

V = IR $\Rightarrow$ I

= $\frac{5 \times 10^{- 3}}{9.9 \times 10^{- 3}}$

= 0.5A ; = 500mA

Read lesson note on Current Electricity (JAMB)

Current Electricity

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Question 14 Report

A mass of gas at 7oC and 70cm of mercury has a volume of 1200cm3. Determine its volume at 27oC and pressure of 75cm of mercury.

1200cm3

1378cm3

4320cm3

4629cm3

Answer Details

\frac{V_{1} P_{1}}{T_{1}}

=

\frac{V_{2} P_{2}}{T_{2}}

$\frac{70 \times 1200}{7 \times 273}$ = $\frac{75 \times V_{2}}{27 + 273}$

V2 = 1200cm3

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Quantity Of Heat

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Question 15 Report

The air column as shown above is set into vibration by the turning fork. In this State of resonance, the waves in the air column will be

stationary and transverse

stationary and longitudinal

progressive and transverse

progressive and longitudinal

Sound Waves

Scalars And Vectors

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Question 16 Report

The electrochemical equivalent of silver is 0.0012gC-1. If 36.0g of silver is to be deposited by electrolysis on a surface by passing a steady current for 5.0mins, the current must be

6000A

100A

10A

1A

Electric Cells

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Question 17 Report

The magnification of the image of an object placed in front of a convex mirror is $ \frac{1}{3} $. If the radius of curvature of the mirror is 24cm, what is the distance between its object and its image?

8cm

16cm

24cm

32cm

Answer Details

F = uv ; v = 1u

12 = $\frac{v + 3 v}{v + 3 v}$

v = 16cm, u = 48cm

distance between U and V

= 48 - 16 =32cm

Read lesson note on Electrostatics (JAMB)

Electrostatics

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Question 18 Report

The figure above shows a conductor PQ carrying a current I in the direction shown. At a particular position near the conductor is a compass needle K. Neglecting the earth's magnetic field, the compass needle will

settle in any direction

settle in a fixed direction only if the conductor PQ is a magnetic material

settle in a fixed direction WHETHER the conductor PQ is a magnetic material OR NOT

be stationary

Magnets And Magnetic Fields

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Question 19 Report

From the kinetic theory of gases, temperature is a

form of energy and is proportional to the total kinetic energy of the molecules

form of energy and is proportional to the average kinetic energy of the molecules

physical property and is proportional to the total kinetic energy of the molecules

physical property and is proportional to the average kinetic energy of the molecules

Structure Of Matter And Kinetic Theory

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Question 20 Report

A block of mass m is held in equilibrium against a vertical wall by a horizontal force. If the coefficient of friction between the wall and the block is µ, the minimum value of the horizontal force is

µmg

(1-µ)mg

(1+µ)mg

mg/µ

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Question 21 Report

A bar magnet is most effectively demagnetized by

placing it in a N - 5 position and hitting it with a hammer

subjecting it to an electric current from a battery

bringing its north pole in contact with the north pole of a very strong magnet

heating the magnet

Magnets And Magnetic Fields

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Question 22 Report

The pressure on the gas of constant gas thermometer at the ice point is 325mm of mercury and at the steam point is 875mm of mercury. Find the temperature when the pressure of the gas is 190mm of mercury

30k

243k

300k

3003k

Answer Details

100

θ

.... 875mm

0 $θ$ ....325mm

$θ$ .... 190mm

$\frac{0 - θ}{100 - θ}$ = $\frac{325 - 190}{875 - 190}$

$θ$ = -25oC

= 243k

Read lesson note on Temperature And Its Measurement (JAMB)

Temperature And Its Measurement

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Question 23 Report

A calibrated potentiometer is used to measure the e.m.f. of a cell because the

internal resistance of a cell is small compared with that of the potentiometer

potentiometer has a linear scale

potentiometer takes no current from the cell

resistance of the potentiometer is less than that of a voltmeter

Electrostatics

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Question 24 Report

A column of air 10.0cm long is trapped in a tube at 27oC. What is the length of the volume at 100oC?

12.4cm

13.7cm

18.5cm

37.0cm

Answer Details

\frac{V_{1}}{T_{1}}

=

\frac{V_{2}}{T_{2}}

$\frac{10 \times A}{27 + 273}$ = $\frac{L \times A}{100 + 273}$

L = 12.43cm

Read lesson note on Temperature And Its Measurement (JAMB)

Temperature And Its Measurement

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Question 25 Report

An electric heater is used to melt a block of ice of mass 1.5kg. If the heater is powered by a 12V battery and a current of 20A flows through the coil, calculate the time taken to melt the block of ice at 0oC. [specific latent heat of fusion of ice = 336 x 103Jkg-1]

76.0min

35.0min

21.0min

2.9min

Heat Energy

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Question 26 Report

When a radiation strikes a metal surface, electrons may be ejected from the metal. The maximum kinetic energy which may be acquired by an ejected electron depend on the

intensity of the radiation

source of the radiation

wavelength of the radiation

detection device of the electron

Electromagnetic Field (Part 2)

Types Of Waves

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Question 27 Report

Which of the following devices are used to measure pressure? i. Aneroid barometer. ii. hydrometer. iii. hygrometer. iv. manometer.

i and iii

ii and iii

iii and iv

i and iv

Description Property Of Fields

Pressure

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Question 28 Report

In the above circuit diagrams A is the ammeter and V is the Voltmeter. Which of the circuits is correct for finding the correct value of the resistance R

I

II

III

IV

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Question 29 Report

The resistance of a 5m uniform wire of cross-sectional area 0.2 x 10-6m2 is 0.425. What is the resistivity of the material of the wire?

1.10 x 10-6

Ω

m

4.25 x 10-6

Ω

m

2.40 x 10-7

Ω

m

1.70 x 10-8

Ω

m

Measurements And Units

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Question 30 Report

A block-and-tackle system is used to lift a load of 20N through a vertical height of 10m. if the efficiency of the system is 40%, how much work is done against friction?

80J

120J

300J

500J

Answer Details

Efficiency =

\frac{o u t p u t}{i n p u t}

x 100

40 = $\frac{20 \times 10}{i n p u t}$ x $\frac{100}{1}$

input = 500J

work against friction = input - output

= 500 - 200 = 300J

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Simple Machines

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Question 31 Report

A thin film of liquid is trapped between two glass plates. The force required to pull the plates apart will increase if the

surface tension of the liquid is reduced

perpendicular distance between the plates is increased

area of the liquid surface in contact with the plates is increased

pressure of the air is decreased

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Question 32 Report

A simple pendulum of mass m moves along an arc pf a circle radius R in a vertical plane as shown above. What is the work done by gravity in a downward swing through the angle q to 0 degree

mgR sinθ

MgR (1- cos θ)

mgR

mgR (1 - sinθ)

Newton’s Laws Of Motion

Gravitational Field

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Question 33 Report

A beam of radiation is passed between a pair of charged plates as indicated in the fig above. Beam P is undetected While Q is deflected to the left. P and Q respectively should be

I.γ-rays β-rays
II. x-rays β-rays
III. γ-rays x-rays
IV. x-rays x-rays

I only

III only

I and II

III and IV

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Question 34 Report

Two points on a velocity time-graph have coordinates (5s, 10ms-1) and (20s, 20ms-1). Calculate the mean acceleration between the two points

0.67ms-1

0.83ms-1

1.50ms-1

2.00ms-1

Motion

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Question 35 Report

A vibrator of frequency 60Hz is used in generating transverse stationary waves in a long thin wire, If the average distance between successive nodes on the wire is 45cm, find the speed of the transverse waves in the wire.

27ms-1

54ms-1

90ms-1

108ms-1

Answer Details

V =

λ

F

= 60 x 45 x 10-2

= 27ms-1

Read lesson note on Production And Propagation Of Waves (WAEC)

Read lesson note on Waves (JAMB)

Production And Propagation Of Waves

Waves

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Question 36 Report

When a number of identical small magnets are arranged in a line, the strength of the resultant magnet

ia largest when they are arranged end to end

is greatest when they are arrangedparallel with like poles adjacent to each other

depends only on the number of magnets provided they arev parallel

is greater when the magnets are arranged on a wooden surface than on a metaln surface

Magnets And Magnetic Fields

Magnetic Field (Part 1)

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Question 37 Report

Three 2-µF capacitors are arranged as seen in the circuit above . The effective capacitance between E and F is

0.75µF

1.33µF

3.00µF

6.00µF

Capacitors

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Question 38 Report

A piece of wood of mass 40g and uniform cross-sectional area of 2cm2 floats upright in water. The length of the wood immersed is

30cm

40cm

20cm

2cm

Position, Distance And Displacement

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Question 39 Report

The plane mirrors in a kaleidoscope are usually placed

at an angle of 60o

parallel to one another

perpendicular to one another

at an angle of 45o

Properties Of Waves: Reflection, Refraction, Diffraction

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Question 40 Report

When the tension in a sonometer wire is doubled, the ratio of the new frequency to the initial frequency is

1

√2

1

2

√2

2

Equilibrium Of Forces

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Question 41 Report

An object is placed at 5.6 x 10-4m in front of a converging lens of focal length 1.0 x 10-nm. The image formed is

Real, Erect and magnified

Virtual, erect and magnified

Real, inverted and magnified

Virtual, erect and diminished

Answer Details

The given problem involves a converging lens, which means it has a positive focal length. The object is placed at a distance of 5.6 x 10^-4 m from the lens. Using the lens formula (1/f = 1/v - 1/u), we can find the image distance (v). 1/f = 1/v - 1/u 1/1.0 x 10^-n = 1/v - 1/5.6 x 10^-4 On simplifying the above equation, we get: v = (1.0 x 10^-n)(5.6 x 10^-4) / (1.0 x 10^-n + 5.6 x 10^-4) We can see that the image distance (v) depends on the value of n. However, regardless of the value of n, we can still determine the nature of the image formed by considering the sign of v. If v is positive, the image is real and located on the opposite side of the lens as the object. If v is negative, the image is virtual and located on the same side of the lens as the object. In this case, the object is placed on the left side of the lens and the lens is converging. Therefore, the image formed will be real and located on the right side of the lens. So, the options (2) and (4) can be eliminated. Now, we need to determine the orientation and size of the image. For this, we can use the magnification formula (m = -v/u), where u is the object distance. m = -v/u = -[(1.0 x 10^-n)(5.6 x 10^-4) / (1.0 x 10^-n + 5.6 x 10^-4)] / (5.6 x 10^-4) On simplifying the above equation, we get: m = -1 / (1 + 1.0 x 10^n/5.6) We can see that the magnification (m) is negative, which means that the image is inverted with respect to the object. Also, the magnitude of the magnification depends on the value of n. However, regardless of the value of n, we can still determine the relative size of the image by considering its absolute value. If |m| > 1, the image is magnified. If |m| < 1, the image is diminished. If |m| = 1, the image is the same size as the object. In this case, the magnitude of the magnification is greater than 1 (i.e., |m| > 1), which means that the image is magnified. Therefore, the correct option is (3) Real, inverted and magnified.

Read lesson note on Structure Of The Atom (Nigeria Only) (WAEC)

Structure Of The Atom (Nigeria Only)

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Question 42 Report

Which of the following is a set of vectors?

force, mass and moment

acceleration, velocity and moment

mass, weight and density

mass, volume and density

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Question 43 Report

Two insulated charged spheres of different sizes and carrying opposite charges are connected together by a metallic conductor. Current will flow from one sphere to the other until both sphere

carry the same magnitude and sign of charge

are at the same potential

are at the same temperature

are of the same size