An electron of mass 9.1 x 10-31 kg moves with a speed of 107ms-1. Calculate the wavelength of the associates wave[h = 6.6 x 10-34Js]
A9.0 x 10-24m
B4.55 x 10-17m
C7.25 x 10-11m
D6.20 x 10-8m
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Question 2
waec2009
The main difference between x-rays and \(\gamma-rays\) lies in their
Aionizing ability
Babsorption rate
Cmode of production
Dmode of propagation
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Question 3
waec2009
Two isotopes of uranium are designed as \(^{238}U\) and \(^{235}U\). The numbers 238 and 235 represent their
Aatomic numbers
Bnucleon numbers
Cproton numbers
Dneutron numbers
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Question 4
waec2009
An ammeter connected to an a.c circuit records 5.5. The peak current in the circuit is
A7.8A
B7.1A
C3.8A
D3.5A
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Question 5
waec2009
An inductor of inductance 1.0H is connected in series with a capacitor of capacitance 2.0\(\mu F\) in an a.c. circuit. to resonate
A112.5Hz
B225.0Hz
C323.5Hz
D707.1Hz
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Question 6
waec2009
If the direction of the curent in a straight wire is reversed, the magnetic field
Aremains the same
Bbecomes parallel to the wire
Cceases to exist
Dis oppositely directed
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Question 7
waec2009
A battery of e.m.f. 12.0V and internal resistance0.5\(\Omega\) is connected to 1.5\(\Omega\) and 4.0\(\Omega\) series resistor. Calculate the terminal voltage of the battery.
A13.0V
B11.0V
C3.0V
D1.0V
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Question 8
waec2009
A wire of resistivity 4.40 x 10-5\(\Omega\) cm has a cross sectional area of 7.50 x 10-4 cm2. Calculate the length of the wire that will be required to make a 4.0\(\Omega\) resistor
A82.50 cm
B68.18cm
C15.90cm
D11.95cm
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Question 9
waec2009
A cell of e.m.f. 1.5V is connected in series with a resistor of resistance 3.0\(\Omega\). A voltmeter connected across the cell registers 0.9V. Calculate the internal resistance of the cell
A2.0\(\Omega\).
B3.0\(\Omega\).
C5.0\(\Omega\).
D6.0\(\Omega\).
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Question 10
waec2009
A resistor of resistance R is connected to a battery of negligible internal resistance. If a siilar resistor is connected in series with it the
Aeffective resistance of the circuit is halved
Btotal power dissipated is doubled
Ctotal current in the circuit is halved
Dterminal voltage is halved
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Question 11
waec2009
An isolated metal sphere of radius R, carrying an electric charge Q, is situated in the medium of relative permitivity, Er. A test charge is placed at a point p, distance r from the surface of the sphere. Let Eo represent the permitivity of free space. The magnitude of the electric field intensity at P is given by the expression
A\(\frac{Q}{4 \pi E_o E_r r^2}\)
B\(\frac{Q}{4 \pi E_o E_r(R + r)^2}\)
C\(\frac{Q}{4 \pi E_o E_r(R - r)^2}\)
D\(\frac{Q}{4 \pi E_o E_rR^2}\)
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Question 12
waec2009
An isolated metal sphere of radius R, carrying an electric charge Q, is situated in the medium of relative permitivity, Er. A test charge is placed at a point p, distance r from the surface of the sphere. Let Eo represent the permitivity of free space. The electric potential at p is given by the expression
A\(\frac{Q}{4 \pi E_o E_r}\)
B\(\frac{Q}{4 \pi E_o E_r (R +r)}\)
C\(\frac{Q}{4 \pi E_o E_r(R - r)}\)
D\(\frac{Q}{4 \pi E_o E_rR}\)
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Question 13
waec2009
When a conductor mounted on an insulating stand is charged and left for sometime, the conductor eventually loses all its charges. This is because the
Aelectric charges evaporate from the surface of the conductor
Bcharges are connected to earth
Ccharges on the conductor are neutralized by opposite charges from the surrounding air
Dcharges ionize the surrounding air
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Question 14
waec2009
A satellite in circular motion around the earth does not have
Aa gravitational force acting on it
Ba uniform velocity
Can acceleration
Da centripetal force acting on it
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Question 15
waec2009
Sound interference is necessary to produce the phenomenon of
Abeats
Bdoppler effect
Cacoustic resonance
Decho
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Question 16
waec2009
Which of the following is not a part of the electro-magnetic spectrum?
Ax-rays
Bmicrowaves
Cinfrared radiation
Dalpha rays
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Question 17
waec2009
Which of the following characteristics of light determines its colour?
Avelocity
Bwavelength
Camplitude
Dintensity
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Question 18
waec2009
A thin lens is placed 50cm from an illustrated object. The image produced has linear magnification of \(\frac{1}{4}\). Calculate the power of the lens in dioptres
A2.5D
B5.0D
C10.0D
D25.0D
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Question 19
waec2009
A concave mirror forms a magnified and errect image only when the object is placed
Aat the centre of curvature
Bat the focus
Cbetween the focus and the pole of the mirror
Dbeyound the radius of curvature
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Question 20
waec2009
The angle of incidence of a ray of light on a plane mirror is 55o. Determine the angle between the reflected ray and the mirror
