I. It is a rapid, constant and irregular motion of tiny particles. II. It gives evidence that tiny particles of matter called molecules exist. III. It takes place only in gases. IV. It gives evidence that molecules are i…
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2012
The quantity of heat energy required to melt completely 1 kg of ice at - 30oC is[latent heat of fusion = 3.5 x 10 5Jkg -1, specific heat capacity of ice = 2.1x10 3Jkg -1K -1]
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2012
A glass block of thickness 10cm is placed on an object. If an observer views the object vertically, the displacement of the object is
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2012
After reflection from the concave mirror, rays of light from the sun converges
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2012
The magnification of an object 2cm tall when placed 10cm in front of a plane mirror is
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2012
A pinhole camera is placed 300m in front of a building so that the image is formed on a screen 5cm from the the pinhole. If the image is 2.5cm high, the height of the building will be
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2012
Where can a man place his face to get an enlarged image when using a concave mirror to shave?
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2012
The fuse in an electric device is always connected to the
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2012
A newly charged 12V accumulator can easily start a car whereas eight new dry cells in series with a effective e.m.f. of 12V cannot start the same car because
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2012
Disperson of white light is the ability of white light to
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2012
The use of lenses is Not applicable in the
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2012
I. Rays of light travel from a less dense medium to a denser medium. II. The Angle of incidence is greater than critical angle. III. Rays of light travel from a denser medium to a less dense medium. Which of the statemen…
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2012
Which of the following particies CANNOT be deflected by both electric and magnetic fields?
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2012
The process of detecting a pin mistakenly swallowed by a child is X-ray
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2012
A conductor of length 1m moves with a velocity of 50ms-1 at an angle of 30o to the direction of a uniform magnetic field of flux density 1.5Wbm-2. What is the e.m.f induced in the conductor?
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2012
The current output from of an a.c. source is given as I = 10 sin to t. The d.c equivalent of the current is
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2012
A particle carrying a charge of 1. 0 x 10-8C enters a magnetic field at 3.0x 10-2 ms -1 at right angles to the field. If the force on this particle is 1.8 x 10-8N, what is the magnitude of the field?
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2012
I. Small size.II. Low power requirementIII. Not easily damaged by high temperatureIV. Highly durable. Which of the above are the advantages of semiconductors?
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2012
If a reverse-biased voltage is applied across a p-n junction, the depletion layer width is
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2012
The p-n junction diodes can act as rectifiers because they