Assertion and Reason
1. What It Is
- Assertion and Reason (A&R) questions test your ability to analyze statements and understand cause-effect relationships.
- You are given two statements:
- Assertion (A) – a statement or fact.
- Reason (R) – an explanation or cause for A.
- You have to determine:
- Whether A is true or false
- Whether R is true or false
- Whether R correctly explains A
Common in exams because they check logical reasoning and comprehension.
2. How to Approach
- Read both statements carefully.
- Check Assertion (A) → true or false?
- Check Reason (R) → true or false?
- Check relationship → if both are true, does R correctly explain A?
- Select correct option according to standard pattern.
3. Rules & Key Points
Standard options in exams:
- Both A and R are true, and R is correct explanation of A ✅
- Both A and R are true, but R is not the correct explanation
- A is true, R is false
- A is false, R is true
Tips:
- Always evaluate A first, then R.
- Even if R is true, it must directly explain A to be correct.
- If A is false → R cannot be the correct explanation.
4. Tricks & Shortcuts
- Highlight keywords in both statements.
- Think cause-effect → does R logically lead to A?
- If A is factually wrong → correct answer involves A false.
- If both A & R are true → verify explanation link carefully.
- Ignore extra details in R if they don’t explain A.
5. Types of Assertion & Reason Questions
- Fact-based – A and R are factual statements.
- Cause-effect – R explains the cause of A.
- Conceptual – A is concept, R is principle or reason.
- Scientific / Technical – A&R from physics, chemistry, computer science, etc.
- Common errors / logic traps – R true but doesn’t explain A.
6. Stepwise Solving Strategy
- Read Assertion → true or false?
- Read Reason → true or false?
- Ask yourself: Does R explain A?
- Match with standard options:
- True/True → explanation correct → option 1
- True/True → explanation wrong → option 2
- True/False → option 3
- False/True → option 4
- Eliminate irrelevant options.
7. Easy Practice Questions
1. Fact-based
Assertion (A): The Earth revolves around the Sun.
Reason (R): The Sun is the center of the Solar System.
Solution:
- A → True
- R → True
- R explains A → Yes ✅
- Answer: Both A & R are true, R is correct explanation of A
2. Cause-Effect
Assertion (A): Metals are good conductors of electricity.
Reason (R): Metals have free electrons that can move easily.
Solution:
- A → True
- R → True
- R explains why metals conduct electricity → Yes ✅
- Answer: Both A & R true, R correct explanation of A
3. Conceptual
Assertion (A): Water boils at 100°C at sea level.
Reason (R): Boiling point depends on atmospheric pressure.
Solution:
- A → True
- R → True
- R explains A → Yes ✅
- Answer: Both A & R true, R correct explanation of A
4. False Reason
Assertion (A): The sky appears blue.
Reason (R): The sky reflects the color of the ocean.
Solution:
- A → True
- R → False → incorrect reason
- Answer: A true, R false → option 3
5. True R but not explanation
Assertion (A): Ice floats on water.
Reason (R): Water is a liquid at room temperature.
Solution:
- A → True
- R → True, but not the correct explanation
- Answer: Both true, R is not correct explanation → option 2
8. Difficult Practice Questions
6. Scientific
A: The Sun appears yellow from Earth.
R: The Sun emits yellow light.
Solution:
- A → True
- R → False (Sun emits all visible light; yellow is perception)
- Answer: A true, R false → option 3
7. Conceptual Logic
A: Dividing by zero is undefined.
R: Zero has no reciprocal.
Solution:
- A → True
- R → True → correct explanation ✅
- Answer: Both true, R correct explanation → option 1
8. Computer Science
A: In programming, an array index starts from 0 in C.
R: Arrays store elements in contiguous memory locations.
Solution:
- A → True
- R → True, but does not explain why index starts from 0
- Answer: Both true, R not correct explanation → option 2
9. Logical Trap
A: Steel is stronger than wood.
R: Wood is lighter than steel.
Solution:
- A → True
- R → True, but unrelated → does not explain A
- Answer: Both true, R not explanation → option 2
10. Technical
A: Air has mass.
R: Air exerts pressure on objects.
Solution:
- A → True
- R → True, but pressure is not the reason air has mass
- Answer: Both true, R not correct explanation → option 2
✅ Quick Tips
- Always evaluate A first, then R.
- Check explanation link, not just truth.
- Beware of true R but irrelevant to A.
- Eliminate options systematically → 4 options always standard.
- Practice with science, reasoning, and general facts → helps recognize patterns.