Q 1 :

Choose the incorrect statement about Dalton's Atomic Theory.               [2024]

• All the atoms of a given element have identical properties including identical mass.

   

• Chemical reactions involve reorganization of atoms.

   

• Compounds are formed when atoms of different elements combine in any ratio.

   

• Matter consists of indivisible atoms.

   

Q 2 :

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:                     [2024]

• (B), (D), (E) only

   

• (B), (D) only

   

• (A), (B), (D) only

   

• (C), (D), (E) only

   

Q 3 :

Following figure shows spectrum of an ideal black body at four different temperatures. The number of correct statement/s from the following is _________.       [2023]

A.  $T_4>T_3>T_2>T_1$

B.  The black body consists of particles performing simple harmonic motion.

C.  The peak of the spectrum shifts to shorter wavelength as temperature increases.

D.  $\frac{T_1}{{\nu }_1}=\frac{T_2}{{\nu }_2}=\frac{T_3}{{\nu }_3}\ne \text{constant}$

E.  The given spectrum could be explained using quantisation of energy.

Q 4 :

The number of incorrect statement/s about the black body from the following is _________            [2023]

(A) Emit or absorb energy in the form of electromagnetic radiation.

(B) Frequency distribution of the emitted radiation depends on temperature.

(C) At a given temperature, intensity vs frequency curve passes through a maximum value.

(D) The maximum of the intensity vs frequency curve is at a higher frequency at higher temperature compared to that at lower temperature.