1.
When zero of the polynomial is substituted in the polynomial, its value is
Correct Answer
C. 0
Explanation
When zero is substituted into a polynomial, it means that we are replacing all the variables in the polynomial with zero. In this case, when we substitute zero into the polynomial, the value of the polynomial becomes zero. This is because any term in the polynomial that contains a variable multiplied by zero will also become zero. Therefore, the correct answer is 0.
2.
Expression for area of a square represents --- in a graph
Correct Answer
B. Parabola
Explanation
The expression for the area of a square does not represent a straight line because the area of a square is not a linear function of its side length. It also does not represent both a straight line and a parabola because a parabola is a curve, not a straight line. Therefore, the correct answer is that the expression for the area of a square represents a parabola in a graph.
3.
55 is which type of polynomial ?
Correct Answer
D. Constant
Explanation
A constant polynomial is a polynomial of degree zero, which means it has no variable terms. In this case, the number 55 can be considered as a constant polynomial because it is a single term with no variables.
4.
(x+y)(x^2-xy+y^2) =
Correct Answer
B. X^3+y^3
Explanation
The given expression is a product of two binomials. By using the distributive property, we can expand the expression to get x^3 - xy^2 + xy^2 - y^3. The middle terms cancel out, leaving us with x^3 - y^3. Therefore, the correct answer is x^3 + y^3.
5.
Zero of the polynomial is always zero ?
Correct Answer
B. False
Explanation
The statement "zero of the polynomial is always zero" is false. A zero of a polynomial refers to a value that makes the polynomial equal to zero. However, not all polynomials have zero as a solution. Some polynomials may have complex roots or no real roots at all. Therefore, it is incorrect to say that the zero of a polynomial is always zero.
6.
Factors of x^2-5x+6________________
Correct Answer
x-3
x-2
Explanation
The given expression is a quadratic equation in the form of x^2-5x+6. To find the factors of this equation, we need to factorize it. We can rewrite the equation as (x-3)(x-2), which represents the product of two binomials. Therefore, the factors of x^2-5x+6 are (x-3) and (x-2).
7.
Is (2x)^-1 a polynomial ?
Correct Answer
B. False
Explanation
The expression (2x)^-1 is not a polynomial because a polynomial is an algebraic expression with one or more terms, where each term consists of a variable raised to a non-negative integer exponent. In this case, (2x)^-1 is equivalent to 1/(2x), which includes a fraction with a variable in the denominator. Therefore, it does not meet the criteria of a polynomial.
8.
Degree of zero polynomial is ?
Correct Answer
B. Undefined
Explanation
The degree of a polynomial is the highest power of the variable in the polynomial. A zero polynomial is a polynomial where all the coefficients are zero. Since there are no terms with non-zero coefficients in a zero polynomial, there is no highest power of the variable. Therefore, the degree of a zero polynomial is undefined.
9.
Is -3 a zero of the polynomial 9- x^{2 }?
Correct Answer
A. True
Explanation
Since a zero of a polynomial is a value that makes the polynomial equal to zero, we can substitute -3 into the polynomial 9 - x^2. When we do this, we get 9 - (-3)^2 = 9 - 9 = 0. Therefore, -3 is indeed a zero of the polynomial, making the statement true.
10.
Binomial, Trinomial, Monomial comes under which classification ?
Correct Answer
D. No.of terms
Explanation
Binomial, Trinomial, and Monomial are classifications based on the number of terms in a polynomial. A monomial has only one term, a binomial has two terms, and a trinomial has three terms. Therefore, the correct classification for these polynomial types is based on the number of terms they have.
11.
Cell(battery) needs to be charged when …..
Correct Answer
A. Its discharged
Explanation
The correct answer is "its discharged" because when a cell battery is discharged, it means that it has used up all of its stored energy and needs to be recharged. This is the most common reason for needing to charge a cell battery. The other option, "chemical inside it is exhausted," is not entirely accurate as the chemical reaction inside the battery is what produces the energy, and it is not necessarily completely exhausted when the battery needs to be charged.
12.
Lightning is an example of
Correct Answer
D. Both A and C options
Explanation
Lightning is an example of both charge transfer and electrostatic discharge. Charge transfer refers to the movement of electric charge from one object to another, which occurs during a lightning strike. Electrostatic discharge, on the other hand, is the sudden flow of electricity between two objects with different electric potentials, which is also observed during a lightning strike. Therefore, both options A and C are correct.
13.
Both ends of a battery can be connected together directly.
Correct Answer
B. False
Explanation
The statement is false because connecting both ends of a battery directly would create a short circuit, which can be dangerous. A short circuit occurs when the positive and negative terminals of a battery are directly connected, causing a large current to flow rapidly. This can lead to overheating, damage to the battery, and potential hazards such as fire or explosion. Therefore, it is important to avoid connecting both ends of a battery directly.
14.
The arrangement of positive charged ions is called ...
Correct Answer
D. Lattice
Explanation
A lattice refers to the arrangement of positive charged ions in a regular, repeating pattern. This arrangement is commonly found in ionic compounds, where positive ions are surrounded by negative ions in a three-dimensional grid-like structure. The lattice structure is responsible for the characteristic properties of ionic compounds, such as their high melting and boiling points, brittleness, and ability to conduct electricity when dissolved in water.
15.
Following Picture shows
Correct Answer
B. a lattice
16.
Conductors have free electrons to move
Correct Answer
A. True
Explanation
Conductors have free electrons to move because the outermost electrons of the atoms in a conductor are loosely bound and can easily move from one atom to another. This allows for the flow of electric current through the conductor.
17.
Insulators have no free electrons to move
Correct Answer
A. True
Explanation
Insulators are materials that do not conduct electricity well because they have a complete valence shell of electrons, which means they have no free electrons to move. This lack of free electrons prevents the flow of electric current through the material, making the statement "Insulators have no free electrons to move" true.
18.
When mercury is heated it changes into ...
Correct Answer
mercury calx
Explanation
When mercury is heated, it undergoes a chemical reaction and forms a compound called mercury calx. This compound is a solid substance that is different from the liquid mercury. The process of heating mercury causes the atoms to rearrange and combine with oxygen from the air, resulting in the formation of mercury calx. This reaction is reversible, and the mercury calx can be further heated to obtain pure liquid mercury again.
19.
Colour of mercuric oxide ?
Correct Answer
C. Red
Explanation
The correct answer is red because mercuric oxide is a compound that appears as a red powder or crystals.
20.
Respiration is an oxidation reaction
Correct Answer
A. True
Explanation
Respiration is an oxidation reaction because it involves the breakdown of glucose molecules in the presence of oxygen to produce carbon dioxide, water, and energy in the form of ATP. During this process, the glucose molecules are oxidized, meaning they lose electrons, while oxygen is reduced, meaning it gains electrons. This transfer of electrons is a characteristic of oxidation reactions. Therefore, it can be concluded that respiration is indeed an oxidation reaction.
21.
Choose the correct spelling
Correct Answer
B. Antoine Lavoisier
Explanation
Antoine Lavoisier is the correct spelling because it matches the commonly known and accepted spelling of the famous French chemist's name. The other options, Antone Lavosir, Antonia Lavvoiser, and Antone Lavosier, do not match the widely recognized spelling of his name.
22.
Lime water chemical formula ?
Correct Answer
A. Ca(OH)_{2}
Explanation
The correct answer is Ca(OH)2. This is the chemical formula for lime water, which is a solution of calcium hydroxide. Lime water is commonly used in various applications, including as a reagent in laboratory experiments and as a supplement for treating calcium deficiencies in plants and animals. The formula Ca(OH)2 indicates that each molecule of lime water consists of one calcium atom bonded to two hydroxide ions.
23.
In human beings exchange of gases happen in ?
Correct Answer
B. Alveoli
Explanation
The exchange of gases in human beings occurs in the alveoli. Alveoli are tiny air sacs located at the end of the bronchioles in the lungs. They are surrounded by capillaries, where oxygen from the inhaled air diffuses into the bloodstream, and carbon dioxide, a waste product, diffuses out of the bloodstream into the alveoli to be exhaled. This process is essential for the oxygenation of the blood and removal of carbon dioxide, allowing for proper respiration and the supply of oxygen to the body's cells.
24.
Constant term of x^{2}+6x-9
Correct Answer
C. -9
Explanation
The constant term of a quadratic equation is the term that does not have any variable attached to it. In the given equation, x^2 + 6x - 9, the constant term is -9.
25.
If P(x) is a polynomial with highest power of the variable as 'n', then 'n' is called as
Correct Answer
degree
Explanation
In the context of polynomials, the highest power of the variable is referred to as the degree. It represents the highest exponent in the polynomial expression. The degree of a polynomial helps determine its characteristics, such as the number of roots or the behavior of the polynomial as the variable approaches infinity or negative infinity. Therefore, in this case, "n" is called the degree of the polynomial P(x).
26.
How many alveoli are present in the human body ?
Correct Answer
C. Millions
Explanation
The answer is millions because the human body contains millions of alveoli. Alveoli are small air sacs located at the end of the bronchioles in the lungs. They are responsible for the exchange of oxygen and carbon dioxide during respiration. The large number of alveoli allows for a large surface area for efficient gas exchange, ensuring that oxygen is delivered to the bloodstream and carbon dioxide is removed from the body.
27.
Mysterious substance in combustion in earlier days was
Correct Answer
D. Phlogiston
Explanation
In earlier days, the concept of phlogiston was widely believed to explain combustion. It was believed that all combustible substances contained an invisible substance called phlogiston, which was released during combustion. This theory was used to explain why substances lost weight when burned. However, this theory was later proven to be incorrect and replaced by the modern understanding of combustion.
28.
Who named oxygen
Correct Answer
B. Lavoisier
Explanation
Lavoisier named oxygen. Antoine Lavoisier, a French chemist, is credited with discovering and naming oxygen in the late 18th century. He conducted experiments and demonstrated that oxygen was a key component of combustion and respiration. Lavoisier also proposed the name "oxygen" for the element, derived from the Greek words meaning "acid-former" due to its role in the formation of acids. His work laid the foundation for modern chemistry and he is often referred to as the "Father of Modern Chemistry."
29.
Who discovered oxygen ?
Correct Answer
B. Priestley
Explanation
Priestley is the correct answer because he is credited with the discovery of oxygen. Joseph Priestley, an English chemist, conducted experiments in the 1770s where he isolated a gas that he called "dephlogisticated air," which we now know as oxygen. His work was crucial in understanding the role of oxygen in combustion and respiration, leading to significant advancements in the field of chemistry. Lavoisier, on the other hand, played a significant role in the understanding of oxygen and its properties but did not actually discover it.
30.
CO_{2 }does not turn lime water milky
Correct Answer
B. False
Explanation
CO2 does not turn lime water milky. This statement is false. When carbon dioxide (CO2) is passed through lime water (calcium hydroxide solution), it reacts with the calcium hydroxide to form calcium carbonate, which is insoluble and appears as a milky white precipitate. Therefore, the correct answer is False.
31.
The portion of bulb which glows is called
Correct Answer
D. Filament
Explanation
The portion of the bulb that glows is called the filament. The filament is a thin wire made of tungsten that is heated up by the flow of electricity, causing it to emit light. It is designed to have a high melting point and low evaporation rate, allowing it to withstand the high temperatures generated when electricity passes through it. The filament is enclosed in a glass bulb to protect it from oxidation and to create a vacuum or fill it with an inert gas to prevent combustion.
32.
Value of the polynomial P(x)=x^{2}-0.03, when x=1/5 is ?
Correct Answer
D. 0.01
Explanation
When we substitute x=1/5 into the polynomial P(x)=x^2-0.03, we get P(1/5)=(1/5)^2-0.03=1/25-0.03=0.01-0.03=-0.02. Therefore, the value of the polynomial P(x) when x=1/5 is -0.02.
33.
Degree of quadratic polynomial is
Correct Answer
B. 2
Explanation
The degree of a quadratic polynomial is 2 because the highest power of the variable in a quadratic polynomial is 2. In other words, a quadratic polynomial can be written in the form ax^2 + bx + c, where a, b, and c are constants and a is not equal to 0.
34.
Respiration releases energy
Correct Answer
B. True
Explanation
Respiration is a metabolic process in which cells break down organic molecules to release energy. This energy is stored in the form of ATP (adenosine triphosphate), which is used by cells for various activities. Therefore, it is correct to say that respiration releases energy.
35.
In an open circuit electrons motion is ….
Correct Answer
random
Explanation
In an open circuit, electrons are not constrained by a complete path, so their motion is unrestricted and unpredictable. They move in a random manner, without any specific direction or purpose. Without a closed circuit to guide them, the electrons do not flow in a controlled or organized manner. Therefore, the correct answer is that their motion is random.
36.
Elecrons are
Correct Answer
C. Both of the above
Explanation
Electrons are mobile charge carriers because they have a negative charge and can move freely within a conductive material. This mobility allows them to carry electric charge from one point to another. Therefore, electrons can be considered as both mobile and charge carriers.
37.
Respire is from which language
Correct Answer
D. Latin
Explanation
The word "respire" is derived from Latin. Latin is a classical language that has influenced many modern languages, including English. "Respire" means to breathe or to inhale and exhale. Latin has contributed significantly to the development of scientific and medical terminology, and "respire" is an example of a word that has been borrowed from Latin into English.