Free Vectors and Equilibrium MCQs with Answers
431 Vectors and Equilibrium MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Vectors have magnitude and direction, unlike scalars, and are combined by head-to-tail or parallelogram methods. Work covers rectangular components, equilibrium when the resultant force is zero, the scalar product for work and projections, and the vector product for torque and cross-product direction using the right-hand rule.
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Read the Vectors and Equilibrium notesFree MDCAT chapter notes with key terms431 questions · page 2 of 22
- A. A resultant vector
- B. A unit vector
- C. A null vector
- D. A position vector
Explanation: A vector with magnitude exactly one is called a unit vector, and it is used to specify direction.
Correct answer: A unit vector- A. Addition of vectors
- B. Subtraction of vectors
- C. Multiplication of vectors
- D. Resolution of vectors
Explanation: Composition combines vectors to find their resultant, whereas resolution separates one vector into rectangular components.
Correct answer: Resolution of vectors- A. Zero
- B. Two
- C. Three
- D. None
Explanation: Two unequal vectors cannot have a zero resultant because their magnitudes would have to be equal and opposite.
Correct answer: Three- A. 2N & 5N
- B. 20N & 2N
- C. 3N & 6N
- D. 4N & 1N
Explanation: The resultant of two vectors with magnitudes 3 N and 6 N can range from |6 N - 3 N| = 3 N to 6 N + 3 N = 9 N, so 8 N is possible.
Correct answer: 3N & 6N- A. 18N
- B. 22N
- C. 25N
- D. 30N
Explanation: For vectors of 10 N and 15 N, the resultant must lie between |15 N - 10 N| = 5 N and 15 N + 10 N = 25 N.
Correct answer: 30N- A. Magnitude
- B. Velocity
- C. Direction of vector
- D. Frequency
Explanation: A unit vector has magnitude 1 and is used mainly to specify direction, such as i, j and k along coordinate axes.
Correct answer: Direction of vector- A. 1
- B. 2
- C. 3
- D. 4
Explanation: Physical quantities are commonly divided into two categories: scalars, which have magnitude only, and vectors, which have both magnitude…
Correct answer: 2- A. Rotational equilibrium
- B. Translational equilibrium
- C. Static equilibrium
- D. Both A and C are corret answer
Explanation: Static equilibrium means the body is at rest, whereas dynamic equilibrium involves uniform motion with zero resultant force and, where…
Correct answer: Static equilibrium- A. 1st condition of equilibrium
- B. 2nd condition of equilibrium
- C. Both Ist and 2nd condition of equilibrium
- D. Impossible
Explanation: Complete equilibrium requires both translational equilibrium, with the resultant force equal to 0 N, and rotational equilibrium, with the…
Correct answer: Both Ist and 2nd condition of equilibrium- A. Always at rest
- B. Always in uniform motion
- C. May be at rest or in uniform motion
- D. May be at rest or in motion
Explanation: When the resultant force and resultant torque are zero, a body has no acceleration and can either remain at rest or continue with constant…
Correct answer: May be at rest or in uniform motion- A. ??3 i^ + ??3 j^ + ??3 k^
- B. 1/??3 i^ + 1/??3 j^ +1/ ??3 k^
- C. ??3 / 3 i^ + ??3 / 3 j^ + ??3 / 3 k^
- D. Both B and C are correct
Explanation: Assuming the damaged symbols represent square roots, the vector in b has magnitude √[(1/√3)² + (1/√3)² + (1/√3)²] = √(3 x 1/3) = 1, so it…
Correct answer: Both B and C are correct- A. Zero magnitude
- B. No specified direction
- C. Both A and B are correct
- D. Both A and B are not correct
Explanation: A null vector has magnitude 0, so it has no unique or specified direction because there is no resultant direction to indicate.
Correct answer: Both A and B are correct- A. 30°
- B. 60°
- C. 90°
- D. 120°
Explanation: For two forces of equal magnitude F, the resultant obeys R² = F² + F² + 2F²cosθ.
Correct answer: 120°- A. 1
- B. 2
- C. 3
- D. Infinite
Explanation: A vector can be resolved into components in any number of chosen directions, provided the components combine vectorially to reproduce the…
Correct answer: Infinite- A. X-axis
- B. Normal on a surface
- C. Y-axis
- D. Z-axis
Explanation: The symbol n^ usually represents a unit normal vector, so it points perpendicular to a surface.
Correct answer: Normal on a surface- A. Dimensionless
- B. Dimensional scalar
- C. Negative
- D. All A, B and C are correct
Explanation: A vector may be multiplied by a scalar that is dimensionless, dimensional, or negative.
Correct answer: All A, B and C are correct- A. 2nd
- B. 4th
- C. 3rd
- D. 1st
Explanation: A negative Ax component points left and a positive Ay component points upward, placing the resultant in the second quadrant.
Correct answer: 2nd38. If a vector Ā is making an angle "∅" with positive y-axis then which of the following is correct.?
- A. Ax= ACos∅
- B. Ay= ASin∅
- C. Ay= ACos∅
- D. None
Explanation: When a vector of magnitude A makes an angle φ with the positive y-axis, its y-component is adjacent to the angle, so Ay = A cosφ.
Correct answer: Ay= ACos∅- A. Zero
- B. 30°
- C. 45°
- D. 90°
Explanation: Rectangular components are components along two mutually perpendicular axes.
Correct answer: 90°- A. 30°
- B. 45°
- C. 60°
- D. 90°
Explanation: For A = 2i + 2j, the x- and y-components are both 2, so tanθ = Ay/Ax = 2/2 = 1. Therefore θ = 45° with the positive x-axis.
Correct answer: 45°