Solution 4:
(i) Zone refining: This method is used for production of semiconductors and other metals of very high purity, e.g., 
and 
. It is based on the principle that the impurities are more soluble in the molten state (melt) than in the solid state of the metal. The impure metal in the form of bar is heated at one end with a moving circular heater, as the heater is slowly moved along the length of the rod, the pure metal crystallises out of the melt whereas the impurities pass into the adjacent molten zone. This process is repeated several times till the impurities are completely driven to one end of the rod which is then cut off and discarded.
(ii) Chromatography: It is based on the principle that the different components of a mixture are adsorbed to different extents on an adsorbent. In column chromatography, an adsorbent, such as alumina 
or silica gel is packed in a column. This forms the stationary phase. The mixture to be separated is dissolved in a suitable solvent (mobile phase) and applied to the top of the column. The adsorbed components are extracted (eluted) from the column with a suitable solvent (eluent).
Explain:
(i) Zone refining
(ii) Column chromatography
(i) Zone refining
(ii) Column chromatography
Explain:
(i) Zone refining
(ii) Column chromatography
(i) Zone refining
(ii) Column chromatography
.
)
west of the geographic north. The north tip of the magnetic needle of a dip circle placed in the plane of magnetic meridian points above the horizontal. The horizontal component of the earth’s field is measured to be 
Specify the direction and magnitude of the earth’s field at the location.At a certain location in Africa, a compass points 
and 
carrying currents of 
and 
in the same direction are separated by a distance of 
. Estimate the force on a 
section of wire A.
wire carrying a current of 
is placed inside a solenoid perpendicular to its axis. The magnetic field inside the solenoid is given to be 
. What is the magnetic force on the wire?
and making an angle of 
with the direction of a uniform magnetic field of 
. What is the magnitude of the field 
at a point 
from the wire?
-turns carrying current 
.
is at distance 
from the wire. Find the force acting on the electron if its velocity is directed towards the wire.