1
JEE Main 2024 (Online) 9th April Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency '$$A$$' $$\times 10^{12}$$ hertz and that has a radiant intensity in that direction of $$\frac{1}{{ 'B'}}$$, watt per steradian. '$$A$$' and '$$B$$' are respectively

A
450 and 683
B
540 and $$\frac{1}{683}$$
C
540 and 683
D
450 and $$\frac{1}{683}$$
2
JEE Main 2024 (Online) 9th April Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Compare the energies of following sets of quantum numbers for multielectron system.

(A) $$\mathrm{n}=4,1=1$$

(B) $$\mathrm{n}=4,1=2$$

(C) $$\mathrm{n}=3, \mathrm{l}=1$$

(D) $$\mathrm{n}=3,1=2$$

(E) $$\mathrm{n}=4,1=0$$

Choose the correct answer from the options given below :

A
$$ (\mathrm{E})>(\mathrm{C})>(\mathrm{A})>(\mathrm{D})>(\mathrm{B}) $$
B
$$ (\mathrm{B})>(\mathrm{A})>(\mathrm{C})>(\mathrm{E})>(\mathrm{D}) $$
C
$$ (\mathrm{C})<(\mathrm{E})<(\mathrm{D})<(\mathrm{A})<(\mathrm{B}) $$
D
$$ (\mathrm{E})<(\mathrm{C})<(\mathrm{D})<(\mathrm{A})<(\mathrm{B}) $$
3
JEE Main 2024 (Online) 6th April Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Match List I with List II.

LIST I
Alkali Metal
LIST II
Emission Wavelength in nm
A. Li I. 589.2
B. Na II. 455.5
C. Rb III. 670.8
D. Cs IV. 780.0

Choose the correct answer from the options given below :

A
(A)-(II), (B)-(IV), (C)-(III), (D)-(I)
B
(A)-(III), (B)-(I), (C)-(IV), (D)-(II)
C
(A)-(I), (B)-(IV), (C)-(III), (D)-(II)
D
(A)-(IV), (B)-(II), (C)-(I), (D)-(III)
4
JEE Main 2024 (Online) 5th April Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

The incorrect postulates of the Dalton's atomic theory are :

(A) Atoms of different elements differ in mass.

(B) Matter consists of divisible atoms.

(C) Compounds are formed when atoms of different element combine in a fixed ratio.

(D) All the atoms of given element have different properties including mass.

(E) Chemical reactions involve reorganisation of atoms.

Choose the correct answer from the options given below :

A
(B), (D) only
B
(A), (B), (D) only
C
(B), (D), (E) only
D
(C), (D), (E) only
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