Online Test — Matrices
10 Questions • 15 min • Chapter MCQ
15:00
Question 1 of 10
medium
The order of matrix [1 2 3; 4 5 6] is:
2×2
2×3
3×2
3×3
Explanation: 2 rows, 3 columns → 2×3
Question 2 of 10
medium
A matrix with 3 rows and 1 column is called a:
Row matrix
Column matrix
Square matrix
Zero matrix
Explanation: Column matrix has n=1
Question 3 of 10
medium
Which of the following pairs can be added?
2×3 and 2×3
2×3 and 3×2
3×1 and 1×3
2×2 and 3×3
Explanation: Addition requires same order
Question 4 of 10
medium
If A = [1 2; 3 4], then 2A = ?
[2 4; 6 8]
[1 2; 3 4]
[2 4; 3 4]
[1 4; 6 8]
Explanation: Multiply each element by 2
Question 5 of 10
medium
A scalar is a:
Matrix
Number
Vector
Row
Explanation: Scalar = ordinary number
Question 6 of 10
medium
For matrix addition, which property holds?
A+B = B+A
A+B ≠ B+A
A+B is undefined
A+B = A
Explanation: Addition is commutative
Question 7 of 10
medium
If A = [3 5; 2 7] and B = [1 4; 6 8], find A − B
[2 1; -4 -1]
[4 9; 8 15]
[2 -1; 4 1]
[2 9; -4 -1]
Explanation: Subtract entrywise: 3-1=2, 5-4=1, 2-6=-4, 7-8=-1, giving [2 1; -4 -1].
Question 8 of 10
medium
A 2×3 matrix has how many elements?
5
6
8
12
Explanation: 2×3 = 6 elements
Question 9 of 10
medium
If A is a 3×4 matrix, then 5A has order:
3×4
4×3
15×20
3×20
Explanation: Scalar multiplication doesn't change order
Question 10 of 10
medium
Which matrix is the additive identity?
[1]
[0]
[1 0; 0 1]
[0 0; 0 0]
Explanation: Zero matrix (all zeros)