Step 1: Analyzing the scene composition.
- The examination hall should feature rows of desks and chairs.
- Students should be depicted seated and engaged in writing their exams.
- An invigilator should be present, supervising the students.
Step 2: Creating depth and perspective.
- Utilize linear perspective to add depth to the hall.
- Draw desks in rows, reducing in size as they recede into the background to maintain perspective.
Step 3: Incorporating environmental details.
- Add elements such as windows, doors, ceiling fans, and a wall clock to enhance realism.
- Illustrate students in varied postures, including writing, thinking, or reviewing their answer sheets.
Step 4: Enhancing realism.
- Apply shading techniques to add volume to the desks, chairs, and architectural elements.
- Maintain accurate proportions for students and objects to ensure a realistic composition.
Let $ a_0, a_1, ..., a_{23} $ be real numbers such that $$ \left(1 + \frac{2}{5}x \right)^{23} = \sum_{i=0}^{23} a_i x^i $$ for every real number $ x $. Let $ a_r $ be the largest among the numbers $ a_j $ for $ 0 \leq j \leq 23 $. Then the value of $ r $ is ________.
A temperature difference can generate e.m.f. in some materials. Let $ S $ be the e.m.f. produced per unit temperature difference between the ends of a wire, $ \sigma $ the electrical conductivity and $ \kappa $ the thermal conductivity of the material of the wire. Taking $ M, L, T, I $ and $ K $ as dimensions of mass, length, time, current and temperature, respectively, the dimensional formula of the quantity $ Z = \frac{S^2 \sigma}{\kappa} $ is: