Question
Atomic radius of fcc is

Answer

(b)For the $ fcc $ structure
$4r = {({a^2} + {a^2})^{1/2}}$$ = a\sqrt 2 $
==> $r = \frac{{a\sqrt 2 }}{4} = \frac{a}{{2\sqrt 2 }}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

A wire of resistance $x$ ohm is drawn out, so that its length is increased to twice its original length, and its new resistance becomes $20 \,\Omega$, then $x$ will be ........ $\Omega$
A parallel plate capacitor is made of two square plates of side $a$, separated by a distance $d\,(d  < < a)$. The lower triangular portion is filled with a dielectric of dielectric constant $K$, as shown in the figure. Capacitance of this capacitor is
In an $X-$ ray tube electrons bombarding the target produce $X-$ rays of minimum wavelength $1\; \mathring A$. What must be the energy of bombarding electrons.......$eV$
A bullet of mass $0.01\, kg$ and travelling at a speed of $500\, m/s$ strikes and passes horizontally through a block of mass $2\,kg$ which is suspended by string of string of length $5\,m$. The centre of gravity of the block is found to raise a vertical distance of $0.1\,m$. What is the speed of the bullet after it emerges from the block .......... $\mathrm{m}/ \mathrm{s}$ $[g = 9.8\,m/s^2]$ (time of passing of bullet is negligible)
In the given circuit, rms value of current $\left( I _{ rms }\right)$ through the resistor $R$ is :$..........\,A$
Match List-I with List II.
List-IList - II
(Spectral Lines of Hydrogen for transitions from)(Wavelengths (nm))
A. $n _2=3$ to $n _1=2$I. 410.2
B. $n _2=4$ to $n _1=2$II 434.1
C. $n _2=5$ to $n _1=2$III 656.3
D. $n_2=6$ to $n_1=2$IV 486.1
Two block of masses $10\,kg$ and $4\,kg$ are connected by a spring of negligible mass  and placed on a frictionless horizontal surface. An impulse gives a velocity of $14\, m/s$ to  the heavier block in the direction of the lighter block. The velocity of the centre of mass is ........ $m/s$.
A liquid drop having $6$ excess electrons is kept stationary under a uniform electric field of $25.5\, k\,Vm^{-1}$ . The density of liquid is $1.26\times10^3\, kg\, m^{-3}$ . The radius of the drop is (neglect buoyancy)
The amplification factor of a triode is $20$. Its plate resistance is $10\, kilo\, ohms$. Mutual conductance is
A train moves towards a stationary observer with speed $34\, m/s$. The train sounds a whistle and its frequency registered by the observer is $f_1$. If the speed of the train is reduced to $17\, m/s$, the frequency registered is $f_2$. If speed of sound is $340\, m/s$, then the ratio $f_1/f_2$ is