1. Introduction to Direction Sense Test
Direction Sense Test evaluates a person's ability to determine directions and distances based on given information. It is essential in logical reasoning and competitive exams.
Basic Directions:
- North (↑)
- South (↓)
- East (→)
- West (←)
Intermediate directions: North-East (NE), North-West (NW), South-East (SE), South-West (SW).
2. Key Concepts
- Right Turn: A 90° clockwise turn.
- Left Turn: A 90° counter-clockwise turn.
- Distance: Straight-line or cumulative based on movements.
- Relative Position: Position of one point/person relative to another after movements.
Assume the initial position faces North unless mentioned otherwise.
3. Types of Direction Problems
- Simple Movement: Questions involving basic turns and movements.
- Finding Distance: Calculating the shortest distance between the start and end points.
- Relative Direction: Finding the direction of one point relative to another.
- Complex Movement: A combination of multiple turns and distances.
4. Solving Direction Problems: Step-by-Step Approach
Step 1: Assume the initial direction is North unless specified.
Step 2: Draw a rough diagram of movements on paper.
Step 3: Track turns and distances step-by-step.
Step 4: Calculate the shortest distance using geometry, if required.
Step 5: Identify the final direction or relative position.
5. Example Problems
5.1 Simple Movement
Problem: A person walks 10m North, then 10m East. In which direction is he now from his starting point?
Solution:
- Step 1: Draw the path → 10m North, then 10m East.
- Step 2: The person is in the North-East direction from the starting point.
5.2 Finding Distance
Problem: A person walks 3m North, then 4m East. Find the shortest distance to the starting point.
Solution:
- Draw the path as a right triangle.
- Use Pythagoras Theorem:
$$ Distance = \sqrt{(North)^2 + (East)^2} $$
$$ Distance = \sqrt{(3)^2 + (4)^2} = \sqrt{9 + 16} = 5 \text{ meters} $$
5.3 Complex Movement
Problem: A person walks 10m North, turns right and walks 10m, turns right again and walks 10m. Which direction is he facing now?
Solution:
- Step 1: Start facing North.
- Step 2: Right turn → East.
- Step 3: Second right turn → South.
- Final Direction: South.
6. Direction-Based Shortcuts
- Right Turn: Change direction clockwise (N → E → S → W → N).
- Left Turn: Change direction counter-clockwise (N → W → S → E → N).
- Opposite Directions: North ↔ South, East ↔ West.
- Diagonal Directions: NE ↔ SW, NW ↔ SE.
7. Special Cases
7.1 Opposite Directions
When a person turns two consecutive right or left turns (90° each), the direction becomes opposite:
- Two Right Turns: North → South.
- Two Left Turns: North → South.
7.2 Relative Position
To find the relative position of two points, calculate their horizontal and vertical displacements and determine the direction accordingly.
8. Summary of Key Points
- Right Turn = 90° clockwise.
- Left Turn = 90° counter-clockwise.
- Use Pythagoras Theorem to find the shortest distance.
- Draw a rough diagram to solve complex problems easily.