GK: Class 12 General Q&A · Page 17
3,658 free answers on GK (General) for Class 12 students, across CBSE, ICSE and State boards.
Question & Answer
Questions
- GeneralClass 12All
What is a definition cell?
A cell is the smallest structural and functional unit of life, serving as the basic building block of all living organisms. Think of cells as microscopic factories that perform all the essential processes necessary for life, from converting nutrients into energy to reproducing and responding to their environment. Each cell is enclosed by a protective membrane that controls what enters and exits, maintaining a distinct internal environment that allows life-sustaining chemical reactions to occu
- GeneralClass 12All
What is √(28x² ÷ 9)?
The expression √(28x² ÷ 9) can be simplified to (2x√7)/3 when x is positive, or more precisely, (2|x|√7)/3 for any real value of x. This problem combines several algebraic skills: simplifying radicals, working with variables, and handling division within radicals—all important competencies for Class 10 mathematics. Let's explore the complete simplification process and the mathematical principles involved. Starting with √(28x² ÷ 9),
- GeneralClass 12All
How do you simplify √(28/343)?
To simplify √(28/343), we use the property that the square root of a quotient equals the quotient of the square roots: √(a/b) = √a/√b. Applying this property: √(28/343) = √28/√343. We've already established that √28 = 2√7. Now we need to simplify √343. Factoring 343: 343 = 7³ = 7² × 7 = 49 × 7. Therefore, √343 = √(49 × 7) = √49 × √7 = 7√7. Putting this together: √(
- GeneralClass 12All
What is √(28x²)?
The expression √(28x²) simplifies to 2x√7 when x is positive, or more generally, 2|x|√7 when x can be any real number. This problem combines the simplification of numerical radicals with the handling of variables under square roots, a skill that's essential in Class 10 algebra. Understanding how to simplify radical expressions involving variables prepares you for solving quadratic equations, working with polynomial expressions, and tackling more advanced algebraic manip
- GeneralClass 12All
What is the lowest square number divisible by 28?
The lowest square number (perfect square) divisible by 28 is 196, which equals 14². To understand why this is the answer and how to find it systematically, we need to examine the prime factorization of 28 and apply the rules for perfect squares. This type of problem tests your understanding of both divisibility and the properties of perfect squares, making it a valuable exercise in Class 10 number theory. The systematic approach to finding this answer involves analyzing the prime
- GeneralClass 12All
What perfect squares are near 28?
The perfect squares nearest to 28 are 25 (which equals 5²) on the lower side and 36 (which equals 6²) on the upper side. These are consecutive perfect squares, meaning there are no other perfect squares between them. Knowing the perfect squares surrounding a given number is extremely useful for estimating square roots, checking calculations, and understanding the magnitude of values in Class 10 mathematics. Looking at a broader range, we can identify several perfect squares
- GeneralClass 12All
Which is a perfect square, 28 or 32?
Neither 28 nor 32 is a perfect square. This can be verified quickly by noting that both numbers fall between the consecutive perfect squares 25 (which is 5²) and 36 (which is 6²), meaning neither can be the square of a whole number. Understanding how to identify perfect squares is a fundamental skill in Class 10 mathematics that appears across multiple topics, from simplifying radicals to solving quadratic equations to working with the Pythagorean theorem. To understand why
- GeneralClass 12All
Is √28 a whole number?
No, √28 is not a whole number. Whole numbers are the non-negative integers: 0, 1, 2, 3, 4, 5, and so on. Since √28 ≈ 5.2915026221..., which falls between the whole numbers 5 and 6, it is clearly not itself a whole number. This distinction is important in Class 10 mathematics because it affects how we represent answers, solve equations, and understand number classifications. The fact that √28 is not a whole number is directly related to the fact that 28 is not a
- GeneralClass 12All
Why is 28 not a perfect square?
The number 28 is not a perfect square because there is no whole number that, when multiplied by itself, equals 28. A perfect square is defined as the product of an integer with itself—for example, 25 = 5 × 5, 36 = 6 × 6, and 49 = 7 × 7. Since √28 ≈ 5.2915..., which is not a whole number, we can conclusively state that 28 is not a perfect square. This concept is fundamental to understanding number properties in Class 10 mathematics and has important implicat
- GeneralClass 12All
Is √28 rational or irrational?
The square root of 28 is definitively an irrational number, which means it cannot be expressed as a ratio of two integers (a fraction in the form p/q where p and q are integers and q ≠ 0). This classification is fundamental to understanding number systems in Class 10 mathematics. An irrational number has a decimal representation that neither terminates nor repeats in a pattern, which is why √28 = 5.2915026221... continues infinitely without any repeating sequence. This is distinctly
- GeneralClass 12All
How do you mentally calculate √28?
Mentally calculating √28 involves using a strategic approach that combines knowledge of perfect squares with simple estimation techniques. The most practical method for mental calculation consists of four clear steps that can be performed quickly with practice. First, identify the perfect squares immediately above and below 28: you know that 25 (which is 5²) and 36 (which is 6²) bracket our target number. This immediately tells you that √28 must be between 5 and 6. Secon
- GeneralClass 12All
How to find square roots orally?
Finding square roots orally (mentally) requires a combination of memorization, pattern recognition, and estimation techniques that Class 10 students can develop with practice. The foundation of oral square root calculation is thorough knowledge of perfect squares, which serve as reference points for all mental calculations. You should memorize perfect squares at least from 1² through 15² (which equals 225), and ideally through 20² (which equals 400) or beyond. Having these valu
- GeneralClass 12All
How can I estimate √28 without a calculator?
Estimating √28 without a calculator is an excellent mental math exercise that develops number sense and mathematical intuition. The most straightforward method uses your knowledge of perfect squares to bracket the value between two known square roots. Since you know that 5² = 25 and 6² = 36, you can immediately determine that √28 must fall between 5 and 6. Furthermore, since 28 is much closer to 25 (only 3 units away) than to 36 (8 units away), you can estimate that &rad
- GeneralClass 12All
What is √28 approximately?
The square root of 28 is approximately 5.29 when rounded to two decimal places, or approximately 5.3 when rounded to one decimal place. These approximations provide quick, practical values for use in calculations and real-world applications where extreme precision isn't necessary. Understanding how to approximate values effectively is a valuable skill for Class 10 students, enabling quick mental calculations and estimation techniques that are useful both in examinations and everyday problem-s
- GeneralClass 12All
What is the square root of 28 to five decimal places?
The square root of 28 to five decimal places is 5.29150. This level of precision is more than adequate for most Class 10 mathematics problems and many real-world applications. Understanding different levels of precision and when each is appropriate is an important aspect of mathematical literacy and numerical reasoning. When we say "to five decimal places," we mean that we've calculated the value and then rounded or truncated it at the fifth digit after the decimal point. The complete
- GeneralClass 12All
What is √28 as a decimal?
The square root of 28 expressed as a decimal is approximately 5.2915026221. This decimal representation provides a numerical value that's practical for calculations, measurements, and real-world applications where an exact radical form isn't necessary. Understanding how to work with decimal approximations of irrational numbers is an important skill for Class 10 students, particularly when solving practical problems in physics, engineering, economics, and everyday life situations that require
- GeneralClass 12All
How do I factor 28 to simplify the square root?
Factoring 28 to simplify its square root involves breaking down the number into its prime factors and then identifying which factors form perfect squares that can be extracted from under the radical sign. This systematic approach is fundamental to simplifying radicals and is an essential technique in Class 10 algebra. Understanding the factorization process not only helps with square roots but also strengthens your overall number sense and algebraic manipulation skills. The factorizat
- GeneralClass 12All
What is √28 in simplest radical form?
The simplest radical form of √28 is 2√7. This representation is considered "simplest" because all perfect square factors have been extracted from under the radical sign, leaving only a prime number (7) that cannot be simplified further. Understanding what constitutes simplest radical form is crucial for Class 10 mathematics, as this form is often required in examinations and provides the most elegant way to express irrational square roots. A radical expression is in simple
- GeneralClass 12All
How do you simplify √28?
Simplifying √28 involves a systematic process of factoring the number 28 to identify and extract perfect square factors from under the radical sign. The goal is to express the square root in its simplest radical form, where no perfect square factors (other than 1) remain under the radical. This process is a fundamental skill in Class 10 algebra and demonstrates understanding of both factorization and the properties of radicals. The step-by-step process for simplifying √28
- GeneralClass 12All
What is the positive square root of 28?
The positive square root of 28 is the same as the square root of 28, which equals 2√7 in simplified radical form or approximately 5.2915026221 in decimal form. The term "positive" is specified because every positive number actually has two square roots: one positive and one negative. For example, both 5 and -5, when squared, equal 25. However, when we use the radical symbol √, we're specifically referring to the principal (positive) square root. This convention is standard in math