NEET Physics: Vector. Addition and subtraction Practice Questions
10 free multiple-choice questions on Vector. Addition and subtraction (Kinematics) for NEET Physics, each with the correct answer and a step-by-step explanation. Attempt a question, then reveal the solution to check your reasoning.
Practice thousands more NEET questions in the app →Q1. If the resultant of two vectors is zero, A⃗ + B⃗ = 0, then the relationship between their magnitudes |A⃗| and |B⃗| is:
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Correct answer: B — |A⃗| = |B⃗|
If A⃗ + B⃗ = 0, then A⃗ = -B⃗. This implies that the two vectors must have equal magnitudes and be in exactly opposite directions (i.e., |A⃗| = |B⃗|).
Q2. If two vectors, A⃗ and B⃗, are in the same direction, what is the magnitude of their resultant vector R⃗ = A⃗ + B⃗?
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Correct answer: C — |A⃗| + |B⃗|
When two vectors are in the same direction, their resultant magnitude is the simple sum of their individual magnitudes.
Q3. If two vectors of magnitude 3 and 4 act in the same direction, what is the magnitude of their resultant vector?
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Correct answer: B — 5
When vectors act in the same direction, their magnitudes are added to find the resultant magnitude: 3 + 4 = 7
Q4. When two vectors are in the same direction, the magnitude of their resultant is calculated by:
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Correct answer: C — Adding their magnitudes
If vectors are parallel (in the same direction), their resultant magnitude is the sum of their individual magnitudes.
Q5. Two vectors, P⃗ and Q⃗, have magnitudes of 5 units and 12 units respectively, and the angle between them is 90°. What is the magnitude of the difference vector |P⃗ - Q⃗|?
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Correct answer: A — 13
Using the law of cosines for the difference in magnitude: |P⃗ - Q⃗|² = |P⃗|² + |Q⃗|² - 2|P⃗||Q⃗|cos(90°) = 5² + 12² - 0 = 25 + 144 = 169. Thus, |P⃗ - Q⃗| = √169 = 13.
Q6. If vector A⃗ is 5 units East and vector B⃗ is 5 units North, what is the magnitude of the resultant vector R⃗ = A⃗ + B⃗?
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Correct answer: B — C=7.07 units
Since the vectors are perpendicular, the resultant magnitude is found by R = √(5² + 5²) = √(25 + 25) = √50 ≈ 7.07 units.
Q7. Two forces, 10 N acting North and 10 N acting South, are applied to an object. What is the net force acting on the object?
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Correct answer: B — C=0 N
Since the forces are equal in magnitude and opposite in direction, their vector sum (net force) is zero. 10 N - 10 N = 0.
Q8. Which of the following statements correctly describes the subtraction of two vectors, A⃗ - B⃗?
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Correct answer: D — It is the same as A⃗ + (-B⃗)
Vector subtraction A⃗ - B⃗ is mathematically equivalent to vector addition of A⃗ and the negative of B⃗, i.e., A⃗ + (-B⃗).
Q9. If two vectors A and B are perpendicular to each other, what is the magnitude of their resultant vector (A + B)?
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Correct answer: C — B=A+B
When two vectors are perpendicular, the magnitude of the resultant vector is found using the Pythagorean theorem: R = sqrt(A² + B²).
Q10. If two vectors A⃗ and B⃗ are anti-parallel (opposite directions), then the magnitude of their difference |A⃗ - B⃗| is equal to:
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Correct answer: C — |A⃗| + |B⃗|
If A⃗ and B⃗ are anti-parallel, θ= 180°. |A - B| = √|A|² + |B|² - 2|A||B|cos(180^°) = √|A|² + |B|² + 2|A||B| = √(|A| + |B|)² = |A| + |B|.
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