From the following, choose the element for impurity atoms with which pure silicon should be doped to make it a p-type semiconductor:

The magnetic flux (Φ) through the area of cross-section of a current-carrying coil is proportional to the current (i) i.e., Φ = Li.
(A) L is self-inductance of the coil
(B) The self-inductance of the coil does not depend on its geometry
(C) self-inductance is the electromagnetic analogue of mass in mechanics
(D) The self-inductance of the coil depends on the permeability of the medium inside coil
Choose the correct answer from the options given below:

Three capacitors of capacitances 2 \(\mu F\), 3 \(\mu F\) and 6 \(\mu F\) are connected in series. The combination is connected to a 12 V supply. The respective potential differences across them will be

In the formation of a p-n junction diode, arrange the following processes in sequence.
(A) Diffusion of charge carriers
(B) Drift of charge carriers
(C) Doping
(D) Generation of electric field at the junction
Choose the correct answer from the options given below :

Six identical cells, each of emf 3 V and internal resistance of r, are connected in series to a \( 3 \text{ } \Omega \) resistance. If the net current flowing in the circuit is 2.0 A. The internal resistance of the cell is

For an ac source rated at 220 V, 50 Hz, which of the following statements is correct?

The power factor of an ac circuit having resistance \( R \) and inductance \( L \) connected in series is :

Which of the following is not an alien species in India?

Oparin and Haldane's theory of chemical evolution of life was experimentally supported by:

Answer the question on basis of passage given below :
Lyophobic sols like those of metals (Au, Ag, etc) are unstable and are easily precipitated by addition of electrolytes. However, it is observed that the addition of certain lyophilic colloids like gums, soaps, gelatine, etc. to lyophobic colloids (like a metal sol) render lyophobic colloids difficult to coagulate by the addition of electrolytes. The process is known as 'protection' and the lyophilic colloids are termed as Protective colloids. It is believed that the protective action of the lyophilic colloids is due to the covering up of the particles of the lyophobic colloid by those of the lyophilic colloid. smaller the gold number of a protective colloid, the greater is its protective action. purification of colloidal solution ?
Evidently, Which of the following methods cannot be used for

"Arrange the following in order of increasing boiling points
(A) 1,4-Dichlorobenzene
(B) 1,3-Dichlorobenzene
(C) 1,2-Dichlorobenzene
(D) Chlorobenzene
Choose the correct answer from the options given below:"

The volume of a cube is increasing at the rate of \(27 cm^3 / s\). How fast is the surface area increasing when the length of the cube is 12 cm ?

During bromination of phenol, Lewis acid is not necessary required because of :