A concave mirror has a radius of curvature of 36cm. At what distance from the mirror should an object be placed to give a real image three times the size of the object?
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1992
When an object is placed very close to the pole of a concave mirror, the virtual image obtained is
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1992
Which of the following properties make the convex mirror useful as a driving mirror? i. the image is real. ii. the image is erect. iii. it has a wide field of view. iv. the image is magnified.
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1992
What is the frequency of the sound made by a siren having a disc with 32 holes and making 25 revolution per seconds?
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1992
Calculate the force acting on an electron of charge 1.6 x 10-19C placed in an electric field of intensity 108Vm-1
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1992
The angle between the direction of the earth's magnetic field and the horizontal is called the
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1992
Which of the following arrangements of the components of electromagnetic spectrum is in ascending order of wavelengths?
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1992
If the refractive index of a medium in air is 2.0, what is the critical angle for this medium?
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1992
The speed of light in air is 3 x 108ms-1. What is the speed in glass with a refractive index of 1.50?
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1992
Which of the following apparatus will require the smallest fuse rating for its protection?
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1992
A 5-v battery is connected across the plates of a 2.0\(\mu\)F uncharged parallel plate capacitor. The charge on the capacitor after a long time is
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1992
A wire of length 15m made of a material of resistivity 1.8 x 10-6\(\Omega\)m has a resistance of 0.27\(\Omega\). Determine the area of the wire
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1992
Which of the following factors has no effect on the e.m.f. of a primary cell?
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1992
When an ebolite rod is rubbed with fur, it has
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1992
The threshold of frequency for photoelectric effect depends on the
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1992
In A.C circuit theory, the root means square (r.m.s) current, Irms and the peak (maximum)current Io are related by
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1992
In alternating current theory, the units of impedance, r.m.s. voltage and resonance frequency are respectively equal to
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1992
The maximum permissible current through a galvanometer G of internal resistance 10\(\Omega\) is 0.05A. A resistance R is used to convert G into a voltmeter with a maximum reading of 100V. Find the value of R and how it i…
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1992
The heat produced in a conductor carrying an electric current is
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1992
\(^{27}_{13}Al\) + \(^{1}_{0}n\) \(\Rightarrow\) \(^{24}_{11}Na\) + X