Potassium has a bcc structure with nearest neighbour distance 4.525 Å. Its molecular weight is 39. Its density in kg/m3 is
|
(a) 900 |
(b) 494 |
(c) 602 |
(d) 802 |
(a) 900
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A metal block is exposed to beams of X-ray of different wavelength. X-rays of which wavelength penetrate most
|
(a) 2 Å |
(b) 4 Å |
(c) 6 Å |
(d) 8 Å |
A solid conducting sphere of radius a has a net positive charge 2Q. A conducting spherical shell of inner radius b and outer radius c is concentric with the solid sphere and has a net charge – Q. The surface charge density on the inner and outer surfaces of the spherical shell will be
|
(a) |
(b) |
(c) 0, |
(d) None of the above |
The deflection in a moving coil galvanometer is
|
(a) Directly proportional to the torsional constant |
|
(b) Directly proportional to the number of turns in the coil |
|
(c) Inversely proportional to the area of the coil |
|
(d) Inversely proportional to the current flowing |
A convex lens of focal length 12 cm is made of glass of μ = 
. What will be its focal length when immersed in liquid of μ = 
|
(a) 6 cm |
(b) 12 cm |
(c) 24 cm |
(d) 30 cm |
Energy levels A, B, C of a certain atom corresponding to increasing values of energy i.e.
. If 
are the wavelengths of radiations corresponding to the transitions C to B, B to A and C to A respectively, which of the following statements is correct
|
(a) |
(b) |
(c) |
(d) |
The phenomena involved in the reflection of radiowaves by ionosphere is similar to:
An important spectral emission line has a wavelength of 21 cm. The corresponding photon energy is (h = 6.62 
|
(a) 5.9 |
(b) 5.9 |
(c) 5.9 |
(d) 11.8 |
