Class 11th

This is a long answer type question as classified in NCERT Exemplar

(a) The weight of the body changes during oscillations.

(b) Considering the situations in two extreme positions

we can say mg-N= ma

so at the highest point the platform is accelerating downward.

N=mg-ma

a=w²A

N=mg-mw²A

A= amplitude of motion m=50kg v=2m/s

w=2 $\pi v=4\pi rad/s$

 A= 5cm = 5 $*{10}^{-2}m$

N= 50 $*9.8-50*{\left(4\pi \right)}^2*5*{10}^{-2}=95.5N$

When it is accelerating towards mean position that is vertically upwards

N-mg=ma=Mw²A

N=mg+mw²A

N=m (g+w²A)

N= 50 [9.8+ ${\left(4\pi \right)}^2*5*{10}^{-2}$ ]

N= 884N

Machine reads the normal reaction

Maximum weight =884N

Minimum weight=95.5N

The NCERT Exemplar includes analytical, application-based, and reasoning-type questions. It goes beyond the NCERT textbooks and helps students apply theories like VSEPR, hybridization, and MOT. It helps students to prepare for various entrance exams like NEET and JEE by strengthening their conceptual clarity.

Hybridization predicts the geometry and bond angles in complex molecules and it helps in the understanding of how four equivalent bonds in methane (CH? )  can be formed from atoms like carbon. For observed molecular geometries, it explains the formation of the equivalent orbitals (like sp³, sp², sp).

In molecular shape prediction, VSEPR (Valence Shell Electron Pair Repulsion) theory is important because based on the repulsions between the electron pairs around the central atom, it helps in predicting the three-dimensional shape of molecules. The 3D shape influences the molecule's chemical and physical properties including reactivity, polarity, and intermolecular forces.

The equation can be written as-

A^p+_x  +  B^q- _y ? xA^p+ (aq) +  yB^q-

S moles of A and B dissolves to give x S moles of A^p+ and y S moles of Bq-.

K_sp = [A^p+]^x   [B^q-]^y = [x5]^x [y5]^y

= x^x y ^y 5 ^x+y

Kindly go through the solution

(c) Li

Kindly go through the solution

(c) Al

Kindly go through the solution

(d) +6

Kindly go through the solution

(a)