When two parallel wires carry currents in opposite directions, the force on either wire is
Aaway from the other wire
Bzero, because the currents cancel each other
Ctwice as much as when the currents are in the same direction
Dtowards the other wire
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Question 2132
jamb1987
The direction of the magnetic field at a point in the vicinity of a bar magnet is
Aalways towards the north pole of the magnet
Balways away from the south pole of the magnet
Calong the line joining the point to the neutral point
Din the direction the north pole of a compass needle would point
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Question 2133
jamb1987
A current of 0.5A flows through a resistor when connected to a 40-V battery. How much energy is dissipated in 2 minutes?
A1200J
B1500J
C2400J
D96000J
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Question 2134
jamb1987
When a transformer has more secondary windings than primary windings, it?
Ahas a smaller secondary current
Bhas a greater power output
Cis a step-down transformer
Dincreases the total energy output
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Question 2135
jamb1987
Two capacitance of 6\(\mu\)F and 8\(\mu\)F are connected in series. What additional capacitance must be connected in series with this combination to give a total of 3\(\mu\)F
A3\(\mu\)F
B16\(\mu\)F
C24\(\mu\)F
D30\(\mu\)F
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Question 2136
jamb1987
If the angle of declination in a place is 10oE, calculate the true geographic bearing if the compass reads N40oE
AN50oE
BN40oE
CN30oE
DN25oE
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Question 2137
jamb1987
Four lenses are being considered for use as a microscope objective. Which of the following focal lengths is most suitable?
A-5mm
B+5mm
C-5cm
D+5cm
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Question 2138
jamb1987
A ray of light is incident at an angle of 30o on one top surface of a parallel-sided glass block of refractive index 1.5. The ray finally emerges from the lower surface. What is the angular deviation of the emergent ray?
A60o
B39o
C28o
D0o
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Question 2139
jamb1987
A pool of water appears to be 1.0m deep when viewed vertically from above. If the refractive index of water is 1.33, what is the actual depth of the pool?
A0.750m
B1.013m
C1.330m
D13.3000m
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Question 2140
jamb1987
An object 3.0cm high is placed 60.0cm from a converging lens whose focal length is 20.0cm. Calculate the size of the image formed
A0.5cm
B1.5cm
C2.0cm
D6.0cm
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Question 2141
jamb1987
If an object is placed in front of two mirrors inclined at 90o, how many images will be formed?
Afive
Bfour
Cthree
Dtwo
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Question 2142
jamb1987
When the length I of a piece of wire under constant tension is varied, the relationship of the frequency of the vibration f\(\alpha\)/ is
Af\(\alpha\)/
Bf\(\alpha \frac{1}{I^2}\)
Cf \(\alpha\sqrt I\)
Df\(\alpha \frac{1}{1}\)
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Question 2143
jamb1987
Which of the following statements supports the assumption that light travels in straight lines?
Alight can be diffracted
Ba source of light produces distinct shadows of opaque objects
Ca source of light produces interference patterns on a suitably placed screen
Dlight can be reflected
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Question 2144
jamb1987
The lowest note emitted by a stretched string has a frequency of 40Hz. How many overtones are there between 40Hz and 150Hz?
A1
B2
C3
D4
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Question 2145
jamb1987
Which of the following instruments has a pure tone?
Aguitar
Bvibrating strings
Ctuning fork
Dsiren
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Question 2146
jamb1987
A boat at anchor is rocked by waves whose crest are 100m apart and whose velocity is 25ms-1. At what interval does the wave crest reach the boat?
A2500.00s
B75.00s
C4.00s
D0.25s
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Question 2147
jamb1987
A wave has a frequency of 2Hz and a wavelength of 30cm. The velocity of the wave is
A60.0ms-1
B6.0ms-1
C1.5ms-1
D0.6ms-1
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Question 2148
jamb1987
Calculate the amount of heat required to convert 2kg of ice at 2oC to water at 0oC. [specific heat capacity of ice = 2090Jkg-1oC-1, specific latent heat of fusion of ice = 333kJkg-1]
A666J
B8360J
C666 000J
D674 360J
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Question 2149
jamb1987
Which of the following phenomena explains the fact that a house whose roof is coated with white paint will be cooler in the hot season than one coated with black paint ?
Aconduction
Bconvection
Crefraction
Dreflection
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Question 2150
jamb1987
The vacuum in a thermos flask helps to reduce heat transfer by?
