When a semiconductor is doped with a donor impurity, the number of _______

Two similar magnetic poles having pole strengths in the ratio 1 : 4 are placed 6 cm apart. The distance from a smaller pole in strength where net magnetic field is zero will be :

The resonant frequency of a series LCR circuit with L = 3H, \( C = 27 \mu F \) and R = 20 \( \Omega \) will be:

Huygen's wave theory of light could not explain the phenomenon of :

Read the following statements related to telescopes carefully:
(A) The main considerations of an astronomical telescope are its light gathering power and its resolution.
(B) the ability to observe two objects (very nearly in the same direction) distinctly depends on the diameter of the objective
(C) large-sized lenses which form images that are free from any kind of chromatic aberration and distortions can be made easily
(D) Telescopes with mirror objectives are free from chromatic aberration
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In a single slit diffraction experiment, first minima for \( \lambda_1 = 600 \, \text{nm} \) coincides with first maxima for wavelength \( \lambda_2 \). The value of \( \lambda_2 \) is

The instantaneous power supplied to a capacitor is given by\(P_c=i_m \cos (\omega t) v_m \sin (\omega t)\).
The average power over a complete cycle would be:

Complete the following analogy: \(S _{ N } 2\) : Inversion of configuration; \(S _{ N } 1\) :______________?

Read the following statements regarding energy levels, and identify the correct statements.
(A) The energy of an atom is least when its electron is revolving in an orbit closest to the nucleus
(B) the energy levels of the excited states come closer and closer together as principal quantum number increases
(C) ionisation energy of the hydrogen atom is the minimum energy required to free the electron from the ground state of the hydrogen atom
(D) as the excitation of hydrogen atom increases, the value of minimum energy required to free the electron from the excited atom decreases.
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Let \(\vec{a}, \vec{b}\) be two vectors such that \(|\vec{a}|=2,|\vec{b}|=3, \vec{a} \cdot \vec{b}=4\). Then \(|\vec{a}-\vec{b}|\) is equal to :

Two wires with resistances \( R_1 \) and \( R_2 \) are stretched n times their original length. After stretching, the two wires are connected in parallel. The equivalent resistance of the combination will be:

Identify the correct sequence of given species found in tropical Amazonian rain forest in terms of their increasing number?
(A) Invertebrates
(B) Fishes
(C) Birds
(D) Plants
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Match List - I with List - II.

List - I	List - II
(A) Oxidation of primary alcohol to Aldehyde	(I) Concentrated sulphuric acid
(B) Oxidations of primary alcohol to carboxylic acid	(II) Zn. dust
(C) Dehydration of propanol to propene	(III) \(CrO _3\) in anhydrous medium
(D) Phenol to benzene	(IV) Acidified potassium permanganate

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