The basic principle used behind the working of electron microscope is:
Using charged mirrors to achieve the desired magnification.
Wave nature of electrons.
Electrostatic field created by a beam of electrons.
Magnifying power of very thin aperture convex lenses.
When a current of 2.5 A passes through the primary coil of a transformer of 200 number turns, the magnetic flux linked with the secondary coil having 400 turns is $600 \times 10^{-6} \mathrm{~T} \mathrm{~m}^2$. Find the induced emf in the secondary coil, when the current in the primary coil increases at a rate of $0.2 \mathrm{As}^{-1}$
$1.92 \times 10^{-2} V$
$1.92 \times 10^{-4} V$
$0.92 \times 10^{-4} V$
$0.92 \times 10^{-2} V$
A block of a certain material is heated to a temperature of $500^{\circ} \mathrm{C}$ and then placed on a large ice block. If 1.455 kg of ice melts, find the mass of the block.
Specific heat of the material is $0.39 \mathrm{Jg}^{-1} \mathrm{C}^{-1}$ and heat of fusion of water is $335 \mathrm{Jg}^{-1}$.
0.67 kg
2.5 kg
1.455 kg
2.67 kg
The critical angle for a typical glass air interface is $42^{\circ}$. If a ray of light falls normally on one of the faces of the prism of angle $45^{\circ}$. The emergent ray will:
Go undeviated
Will pass parallel to the second surface
Will undergo refraction with a refracting angle $45^{\circ}$
Undergo total internal reflection from the second face
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