Which of the following is an essential physical property of the wires used for making fuses?
Alow density
Bhigh thermal conductivity
Clow electrical resistivity
Dlow melting point
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Question 2022
jamb1990
The total energy required to send a unit positive charge round a complete electrical circuit is the
Akinetic energy
Bpotential difference
Celectromotive force
Delectrical energy
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Question 2023
jamb1990
When a known standard resistor of 2\(\Omega\) is connected to the 0.0cm end of a meter bridge, the balance point is found to be at 55.0cm. What is the value of the unknown resistor?
A1.10\(\Omega\)
B1.64\(\Omega\)
C2.44\(\Omega\)
D27.50\(\Omega\)
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Question 2024
jamb1990
Three cells each of e.m.f. 1.5v and an internal resistance of 1.0\(\Omega\) are connected in parallel across a load resistance of 2.67\(\Omega\). Calculate the current in the load?
A0.26A
B0.41A
C0.50A
D0.79A
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Question 2025
jamb1990
Which of the following is a vector?
AElectric charge
BElectric field
CElectrical potential difference
DElectrical capacitance
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Question 2026
jamb1990
Which of the following statements are true of an insulated charged body carrying positive charge? i. it contains excess positive charges. ii. it creates an electric field. iii. it possesses potential energy. iv. it carries electric current.
Ai and iv only
Bi and ii only
Ci, ii, iii only
Di, ii, iii and iv
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Question 2027
jamb1990
One of the properties of the earth's magnetic field is that the
Anorth pole lies in the northern hemisphere
Bgeographic and magnetic meridians coincide
Cearth's magnetic flux is entirely horizontal at a place where the magnetic dip is zero
Dearth's magnetic flux is entirely vertical at a place where the magnetic dip is zero
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Question 2028
jamb1990
A sonometer wire of length 100cm under a tension of 10N, has a frequency of 250Hz. Keeping the length of the wire constant, the tension is adjusted to produce a new frequency of 350Hz. The new tension is
A5.1N
B7.1N
C14.0N
D19.6N
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Question 2029
jamb1990
An organic pipe closed at one end is 80cm long. Determine the frequency of the fundamental note assuming that the speed of sound in air is 340ms-1
A106Hz
B213Hz
C318Hz
D425Hz
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Question 2030
jamb1990
In a resonance tube experiment, the effective length of the air column for the first resonance is 20cm when set into vibration by a tuning fork of frequency 480Hz. Neglecting and effect, the velocity of sound in air is
A96ms-1
B255ms-1
C340ms-1
D384ms-1
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Question 2031
jamb1990
When light is incident on an object which is magenta in colour, which of the following colour would be absorbed?
ARed and blue
BGreen only
CRed and green
DRed only
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Question 2032
jamb1990
For a short sighted person, light rays from a point on a very distant object is focused
Ain front of the retina
Bon the retina by a converging lens
Cbehind the retina by a diverging lens
Din front of the retina, a distance 2F from the lens
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Question 2033
jamb1990
What must be the distance between an object and a converging lens of focal length 20cm to produce an erect image two times the object height?
A20cm
B15cm
C10cm
D5cm
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Question 2034
jamb1990
A boy looks at the image of an object in a plane mirror. He observes two images, a main bright one and the other faint. The observed images result from?
Areflection only
Brefraction only
Cdiffraction and interference
Dreflection and refraction
Ereflection and diffraction
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Question 2035
jamb1990
An object which is 3cm high is placed vertically 10cm in front of a concave mirror. If this object produces an image 40cm from the mirror, the height of the image is
A0.75cm
B4.00cm
C8.00cm
D12.00cm
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Question 2036
jamb1990
Shadows and eclipses result from the
Arefraction of light
Brectilinear propagation of light
Cdefraction of light
Dreflection of light
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Question 2037
jamb1990
A wave disturbance travelling in air enters a medium in which its velocity is less than that in air. Which of the following statements is true about the wave medium?
Aboth the frequency of the wave and the wavelength are decreased
Bthe frequency of the wave is decreased while the wavelength is increased
Cthe frequency of the wave is unaltered while the wavelength is decreased
Dthe frequency of the wave is decreased while the wavelength is unaltered
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Question 2038
jamb1990
A light wave of frequency 5 x 10\(^{14}\)Hz moves through water which has a refractive index of \(\frac{4}{3}\). Calculate the wavelength in water if the velocity of light in air is 3 x 10\(^8\)ms\(^{-1}\)
A4.5 x 10-7m
B6.0 x 10-7m
C1.7 x 106m
D2.2 x 106m
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Question 2039
jamb1990
Which of the following statements are correct? i. land and sea breezes are natural convection currents. ii. convection may occur in liquids or gasses but not in solids. iii. the vacuum in a thermos flask prevents heat loss due to convection only.
Ai and ii only
Bi and iii only
Ci and iii only
Di, ii, and iii
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Question 2040
jamb1990
Which of the following conditions will make water boil at a temperature of 100oC when the atmospheric pressure is 750mmHg?
