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| Maths Quiz for Class 7 Powers and Exponents |
In this post, you will find 20 online maths quiz questions
for class 7 powers and exponents. Online maths quiz will take around 20 minutes
to complete it.
Question 1: The exponential form of 243 is ________.
A) 33
B) 34
C) 35
D) 36
Explanation: 243 = 3 × 3 × 3 × 3 × 3 = 35
Question 2: Find the value of 54.
A) 625
B) 125
C) 75
D) 25
Explanation: 54 = 5 × 5 × 5 × 5 = 625
Question 3: Express 1225 as a product of the powers of prime factors.
A) 52 × 72
B) 25 × 27
C) 53 × 72
D) 52 × 73
Explanation: We have 1225 = 5 × 245 = 5 × 5 × 49 = 5 × 5 × 7 × 7 = 52 × 72
Question 4: Which of the following is the greatest?
A) 72
B) 27
C) 34
D) 43
Explanation: 72 = 7 × 7 = 49, 27 = 2 × 2 × 2 × 2 × 2 × 2 × 2 = 128, 34 = 3 × 3 × 3 × 3 = 81, 43 = 4 × 4 × 4 = 64. So, 27 is the greatest.
Question 5: Which of the following is the smallest?
A) 35
B) 53
C) 54
D) 36
Explanation: 35 = 3 × 3 × 3 × 3 × 3 = 243, 53 = 5 × 5 × 5 = 125, 54 = 5 × 5 × 5 × 5 = 625, 36= 3 × 3 × 3 × 3 × 3 × 3 = 729. So, 53 is the smallest.
Question 6: Find the value of (-2)6.
A) -64
B) 32
C) 64
D) -32
Explanation: (-2)6 = (-2) × (-2) × (-2) × (-2) × (-2) × (-2) = 64
Question 7: Find the value of (-5)5.
A) 3125
B) -3125
C) 625
D) -625
Explanation: (-5)5 = (-5) × (-5) × (-5) × (-5) × (-5) = -3125
Question 8: Express the following in the exponential form: x × x × y × y × y × z × z × z × z
A) x3y4z5
B) x2y4z4
C) x2y3z5
D) x2y3z4
Explanation: x × x × y × y × y × z × z × z × z = x2y3z4
Question 9: Evaluate: (-5)3 × (-3)5
A) 30375
B) -30375
C) 30475
D) 30425
Explanation: (-5)3 × (-3)5 = (-5) × (-5) × (-5) × (-3) × (-3) × (-3) × (-3) × (-3) = (-125) × (-243) = 30375
Question 10: 35 × 36 × 37 = ___________
A) 311
B) 313
C) 318
D) 312
Explanation: 35 × 36 × 37 = 35+6+7 = 318 (using first law of exponents)
Question 11: 713 ÷ 78 = ___________
A) 721
B) 75
C) 76
D) 74
Explanation: 713 ÷ 78 = 713-8 = 75 (using second law of exponents)
Question 12: (46)3 = _______
A) 49
B) 418
C) 42
D) 43
Explanation: (46)3 = 46 x 3 = 418
Question 13: 39 × 59 = _______
A) 159
B) 89
C) 1518
D) 818
Explanation: 39 × 59 = (3 × 5)9 = 159
Question 14: (754)0 = ___________.
A) 0
B) 754
C) 377
D) 1
Explanation: (754)0 = 1 (Any non-zero number raised to power 0 is always 1)
Question 15: Find the value of x in the following: 81 × 3x = 39
A) x = 4
B) x = 3
C) x = 5
D) x = 6
Explanation: 81 × 3x = 39 => 34 × 3x = 39 => 34+x = 39 => 4 + x = 9 => x = 9 – 4 => x = 5
Question 16: Find the value of x in the following: 256 ÷ 2x = 25
A) x = 4
B) x = 3
C) x = 2
D) x = 5
Explanation: 256 ÷ 2x = 25 => 28 ÷ 2x = 25 => 28-x = 25 => 8 – x = 5 => x = 8 – 5 => x = 3
Question 17: Evaluate: [76 × 49] ÷ 75
A) 73
B) 74
C) 75
D) 72
Explanation: [76 × 49] ÷ 75 = [76 × 72] ÷ 75 = 76 + 2 ÷ 75 = 78 ÷ 75 = 78-5 = 73
Question 18: Write a number for: 5 × 107 + 7 × 105 + 9 × 104 + 3 × 102 + 6 × 100
A) 5790306
B) 5079306
C) 50790306
D) 5079036
Explanation: 5 × 107 + 7 × 105 + 9 × 104 + 3 × 102 + 6 × 100 = 50000000 + 700000 + 90000 + 300 + 6 = 50790306
Question 19: Express the following number in scientific notation: 3870500000
A) 3.8705 × 108
B) 3.8705 × 109
C) 38705 × 109
D) 3.875 × 109
Explanation: 3870500000 = 3.8705 × 1000000000 = 3.8705 × 109
Question 20: Express the following number in usual form: 5.038 × 107
A) 5038000
B) 503800
C) 50380000
D) 503800000
Explanation: 5.038 × 107 = 5.038 × 10000000 = 50380000
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