Foundation Physics Class 11 [pcb]

Classical physics, as a branch of physics developed before the 20th century, focused on macroscopic phenomena and did not include the study of elementary particles. Instead, it primarily dealt with mechanics, heat, and sound, which are all macroscopic phenomena. The study of elementary particles emerged with the development of quantum mechanics in the early 20th century, which revolutionized our understanding of the microscopic world. Therefore, elementary particles were not considered within the scope of classical physics.

Botanical gardens and zoological parks typically have a collection of both endemic and exotic living species. Endemic species refer to those that are native and exclusive to a particular region or habitat. These gardens and parks aim to preserve and showcase the biodiversity of a specific area, which includes both endemic species and exotic species that are not native to the region but are kept for educational or conservation purposes. Therefore, the correct answer is the collection of endemic and exotic living species.

Gerontology is the study of ageing. It involves understanding the physical, psychological, and social aspects of the ageing process. Gerontologists examine the effects of ageing on individuals and society as a whole, including the changes that occur in the body, the impact on mental health, and the social implications of an ageing population. They also explore strategies to promote healthy ageing and improve the quality of life for older adults.

The correct answer is that reproductive parts are more conservative. This means that the reproductive structures of angiosperms, such as the flowers and their parts, tend to be more consistent and less variable compared to other features. This makes them reliable for identification purposes as they provide consistent characteristics that can be used to distinguish different species. The other options, such as flowers being nice to work with, having various colors and scent, or being safely pressed, are not valid reasons for using floral features for identification.

The zero of the circular scale being 4 divisions below the reference line means that the screw gauge is not properly calibrated. The least count of the screw gauge is 0.001 cm, which means that each division of the circular scale represents 0.001 cm. Since the zero is 4 divisions below the reference line, the zero correction would be 4 divisions multiplied by the least count, which is 4 * 0.001 cm = 0.004 cm. Therefore, the correct answer is - 0.004 cm.

The dimensional formula [ ML2T-1 ] represents angular momentum. This is because angular momentum is defined as the product of moment of inertia (mass times the square of distance) and angular velocity (radians per unit time). Therefore, the dimensional formula for angular momentum includes the dimensions of mass (M), length (L), and time (T), with the exponent of -1 indicating that it is divided by time.

All of the given options - Urea, Sodium nitrate, and Ammonium sulphate - are chemical fertilizers. Chemical fertilizers are synthetic substances that provide essential nutrients to plants to promote their growth and increase crop yields. Urea is a commonly used nitrogen-based fertilizer, Sodium nitrate is a source of nitrogen and potassium, and Ammonium sulphate is a nitrogen and sulfur-based fertilizer. Therefore, all of these options are correct as they are chemical fertilizers.

Water potential is a measure of the potential energy of water to move from one place to another. Pure water has the highest water potential, which is defined as 0. This means that there is no resistance or solute potential in pure water, allowing it to freely move and diffuse. Therefore, the correct answer is 0.

When adding numbers with different decimal places, it is important to consider significant figures. In this case, 0.9825 has 4 significant figures and 3.04 has 3 significant figures. When adding these numbers, the result should have the same number of decimal places as the number with the fewest decimal places, which is 3.04. Therefore, the correct result with regard to significant figures is 4.02.

The dimension of impulse is equal to that of linear momentum because both quantities are related to the change in momentum of an object. Impulse is defined as the change in momentum of an object, which is equal to the product of the force applied to the object and the time interval over which the force is applied. Linear momentum, on the other hand, is a measure of the quantity of motion of an object and is equal to the product of the mass and velocity of the object. Since both impulse and linear momentum involve the change in momentum, their dimensions are the same.

When considering the genotype Ggss, we can determine the possible gametes by separating the two alleles for each gene. In this case, the plant has one allele for green pods (G) and one allele for smooth seeds (s). The possible combinations for these alleles are Gs and gs. Therefore, the correct answer is Gs and gs.

Optical fibers are based on total internal reflection. This phenomenon occurs when light traveling through a medium with a higher refractive index encounters a boundary with a medium of lower refractive index at an angle greater than the critical angle. Instead of refracting out of the medium, the light is reflected back into it. This principle is utilized in optical fibers to guide and transmit light signals over long distances with minimal loss of signal strength.

As we move up the taxonomic hierarchy from species to kingdom, the number of common characteristics will decrease. This is because as we move up the hierarchy, we are grouping together more diverse organisms that share fewer common characteristics. At the species level, organisms are very similar and share many common characteristics. However, as we move up to higher taxonomic levels such as genus, family, order, class, phylum, and finally kingdom, the organisms become more diverse and share fewer common characteristics. Therefore, the number of common characteristics will decrease as we go from species to kingdom.

Hydathodes are specialized structures found in plants that help in the release of excess water through droplets. These droplets are often seen on the tips of leaves or along the leaf margins. In this case, the correct answer is Nerium, as hydathodes are present in this plant species.

The correct answer is Einstein because he made the famous statement that "time is what a clock reads." This statement reflects Einstein's theory of relativity, which revolutionized our understanding of time and space. According to Einstein, time is not an absolute concept but is relative to the observer's frame of reference. This means that time can be experienced differently depending on factors such as gravity and velocity. Einstein's theory has had a profound impact on the field of physics and has been confirmed by numerous experiments and observations.

The equivalent weight of an element can be calculated by dividing the molar mass of the element by the percentage of the element present in its compound. In this case, since the chloride of the element contains 52.8% chlorine, the percentage of the element itself would be 100% - 52.8% = 47.2%. Therefore, the equivalent weight of the element would be the molar mass divided by 47.2%.

During telophase, which is the final stage of mitosis, several important events occur. The nuclear membrane reforms around the separated sets of chromosomes, enclosing them within individual nuclei. The nucleolus, which was dispersed during earlier stages of mitosis, reappears within the newly formed nuclei. Additionally, the astral rays, which are microtubules that help position the spindle apparatus during cell division, disappear. Therefore, all of the given options are correct as they accurately describe the events that take place during telophase.

The 9:3:3:1 dihybrid ratio is due to independent assortment. Independent assortment is the principle that states that during gamete formation, the alleles for different traits segregate independently of one another. This means that the inheritance of one trait does not affect the inheritance of another trait. In this case, the 9:3:3:1 ratio indicates that the alleles for two different traits are segregating independently and combining randomly in the offspring.

The synthesis phase in the cell cycle is called so because it is the phase where DNA synthesis takes place. During this phase, the cell replicates its DNA in preparation for cell division. This ensures that each daughter cell receives an identical copy of the genetic material. Therefore, the correct answer is DNA.

Phylogenetic classification is based on common evolutionary descent, as it aims to group organisms based on their shared ancestry. This classification system considers the evolutionary relationships and genetic similarities between different species to determine their placement within a hierarchical tree-like structure. By identifying common ancestors and tracing the evolutionary history of organisms, phylogenetic classification provides insights into the evolutionary relationships and patterns of diversification among different species.

Ernst Mayr is often referred to as "The Darwin of the 20th century" because of his significant contributions to the field of evolutionary biology. Mayr was a renowned biologist who developed the concept of biological species and made important advancements in understanding speciation and the process of evolution. His work on the theory of allopatric speciation and the role of geographic isolation in driving evolutionary change revolutionized the field. Mayr's extensive research and writings on evolutionary biology have had a profound impact on our understanding of the subject, earning him the nickname "The Darwin of 20th century."

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The molality of a solution is defined as the number of moles of solute per kilogram of solvent. In this case, the solute is HCl gas and the solvent is water. To find the molality, we need to first calculate the number of moles of HCl gas. The molar mass of HCl is 36.46 g/mol. Therefore, the number of moles of HCl gas is 18.25 g / 36.46 g/mol = 0.5 mol. Next, we need to calculate the mass of the water in kilograms, which is 500 g / 1000 = 0.5 kg. Finally, we can calculate the molality by dividing the number of moles of HCl gas by the mass of the water in kilograms: 0.5 mol / 0.5 kg = 1 m.

The dimensional formula for force can be determined by analyzing the given options. The only option that includes all three fundamental units (A, V, and D) is AV2D. Therefore, AV2D is the correct dimensional formula for force.

In the given formula X = 3YZ^2, X represents capacitance and Z represents magnetic induction. The dimensions of capacitance are represented by [M-3L-2T4Q4], and the dimensions of magnetic induction are represented by [M-3L-2T4Q4]. Therefore, the dimensions of Y can be determined by subtracting the dimensions of X and Z from the given formula. Thus, the dimensions of Y in the MKSQ system are [M-3L-2T4Q4].

Chromosomes are visible only during cell division. They are structures made up of DNA and proteins that carry genetic information. During cell division, chromosomes condense and become visible under a microscope. They play a crucial role in the accurate distribution of genetic material to the daughter cells. Outside of cell division, chromosomes are not visible as they are in a less condensed state called chromatin. Mitochondria and chloroplasts are organelles involved in energy production and are visible throughout the cell cycle.

The correct answer is "kmh-1" because it represents speed in kilometers per hour in the SI unit. The "km" stands for kilometers and the "-1" indicates per hour. This notation is commonly used to express speed in the metric system.

The mass percentage of carbon in carbon dioxide is 27.27%. This means that for every 100 grams of carbon dioxide, 27.27 grams of it is carbon.

Dry cobalt chloride paper is blue in color. Cobalt chloride is a chemical compound that changes color when it comes into contact with moisture. When the paper is dry, it appears blue. However, when exposed to moisture, it turns pink. Therefore, the correct answer is blue.

The dimensions of critical velocity vc can be determined using the principle of dimensional analysis. The critical velocity depends on the coefficient of viscosity (n), the density of the liquid (p), and the radius of the tube (r). By analyzing the units of these variables, we can determine the dimensions of vc. Since viscosity is measured in Pa.s, density is measured in kg/m^3, and radius is measured in meters, the dimensions of vc would be [n * p * r]. Therefore, the correct answer is 1, -1, -1.

The thin strip at the back of vernier calipers is used for measuring the depth of a cylinder. The strip allows the calipers to be placed against the edge of the cylinder and extended into its depth, providing an accurate measurement. This feature is particularly useful when precise measurements of the depth of cylindrical objects are required. It is not used for measuring the internal diameter of a beaker or the diameter of a hollow cylinder.

Density is not a dimensionless variable because it is defined as mass per unit volume, and both mass and volume have dimensions. Density is measured in units such as kilograms per cubic meter or grams per milliliter, indicating that it has dimensions associated with it. Therefore, density cannot be considered a dimensionless variable.

The empirical formula of the carbohydrate is CH2O, meaning it contains one carbon atom, two hydrogen atoms, and one oxygen atom. Since it is given that 1 gram of hydrogen is present, we can calculate the molar mass of hydrogen and compare it to the molar mass of the carbohydrate. The molar mass of hydrogen is approximately 1 g/mol, which means that 1 gram of hydrogen is equal to 1 mole of hydrogen atoms. Since there are 0.1 moles of the carbohydrate, the molar mass of the carbohydrate must be approximately 10 g/mol. By dividing the molar mass of the carbohydrate by the molar mass of the empirical formula (30 g/mol), we find that the molecular formula is C5H10O5.

Quartz crystal clocks have an accuracy of 1 second in every 109 seconds. This means that for every 109 seconds that pass, the clock may be off by 1 second. Quartz crystal clocks are known for their high precision and stability, making them commonly used in various timekeeping applications. The accuracy of 1 second in every 109 seconds indicates that these clocks are highly reliable and can provide accurate time measurements over extended periods.

The term "specific epithet" refers to the second part of a binomial name, which is used to identify a specific species within a genus. In this case, "sativa" is the specific epithet for the rice plant, Oryza sativa. Therefore, the correct answer is "specific epithet."

Imbibition is the correct answer because it refers to the process of absorption of water by plant cells due to surface attraction. During imbibition, water molecules are attracted to the cell walls and other surfaces within the plant cells, causing them to be absorbed. This process is important for the hydration and functioning of plant cells. Diffusion refers to the movement of molecules from an area of high concentration to an area of low concentration, osmosis is the movement of water across a semi-permeable membrane, and endosmosis refers to the inward movement of water into a cell.

The correct answer is 10 - 12 months. Honey bee drones have a longer lifespan compared to worker bees. Drones are male bees whose main purpose is to mate with the queen. Once they have fulfilled their mating role, they die. However, during the mating season, drones can live for 10 - 12 months. This extended lifespan allows them to be available for mating opportunities throughout the season.

The term "chromosome" literally means "coloured bodies". This refers to the fact that chromosomes can be stained and observed under a microscope, where they appear as distinct, colored structures. The coloration allows scientists to study and analyze the structure and behavior of chromosomes, which play a crucial role in the inheritance of genetic information.

The correct answer is "Holotype". In taxonomy, a holotype is a single specimen that serves as the basis for the description of a new species. It is typically the first specimen collected or observed by the author and is designated as the reference specimen for that species. The holotype is usually deposited in a museum or herbarium and serves as a permanent reference for future researchers to compare and verify the identity of the species.

1 mm Hg represents a pressure of 133.3 N m-2. This is because 1 mm Hg is equal to 133.3 pascals (Pa), and 1 pascal is equivalent to 1 N m-2. Therefore, 1 mm Hg is equal to 133.3 N m-2.

The number of molecules in a substance is determined by its molar mass and Avogadro's number. The molar mass of CO2 is 44 g/mol, O2 is 32 g/mol, H2 is 2 g/mol, and SO2 is 64 g/mol. Since the molar mass of H2 is the lowest among the given substances, it means that 8g of H2 will have the highest number of molecules. This is because a lower molar mass means that there are more moles of the substance in the given mass, which in turn means a higher number of molecules.

Length cannot be measured by debye because debye is a unit used to measure electric dipole moments in a system. It is not a unit used to measure physical distances or lengths. Fermi, micron, and light year are all units commonly used to measure length or distance in different contexts.

The maximum percentage error in y can be found by adding the percentage errors in a and b. In this case, the percentage error in a is 2% and the percentage error in b is 3%. Therefore, the maximum percentage error in y is 2% + 3% = 5%. However, none of the given options match this calculation, so the correct answer is not available.

The biological concept of species is mainly based on reproductive isolation. Reproductive isolation refers to the barriers that prevent individuals from different populations or species from interbreeding and producing fertile offspring. This concept recognizes that species are distinct biological units that are reproductively isolated from one another. While morphology and methods of reproduction can also play a role in defining species, reproductive isolation is considered the primary factor in determining whether two populations or groups of organisms belong to the same species or not.

The percentage of error in the measurement of the time period of a pendulum can be calculated by taking into account the maximum errors in the measurement of l (length of the pendulum) and g (acceleration due to gravity). Since the maximum error in the measurement of l is 2% and the maximum error in the measurement of g is 4%, the total error can be calculated as the sum of the individual errors, which is 2% + 4% = 6%. To calculate the percentage of error in the time period, we divide the total error by the sum of l and g, which is 6% / 200% = 3%. Therefore, the correct answer is 3%.

The correct answer is n - propanol. This is because n - propanol is a primary alcohol that can react with methyl magnesium bromide to release methane gas. The given information states that 375 mg of the alcohol reacts with the required amount of methyl magnesium bromide and produces 140 ml of methane gas at standard temperature and pressure (S.T.P). Based on this information, n - propanol is the most likely alcohol that fits the given conditions.

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When hydrogen gas (H2) and chlorine gas (Cl2) react, they form hydrogen chloride gas (HCl). The balanced chemical equation for this reaction is:

H2 + Cl2 → 2HCl

From the equation, it can be seen that for every 1 mole of hydrogen gas, 2 moles of hydrogen chloride gas are formed. Therefore, when 22.4 liters of H2 (which is 1 mole at STP) is mixed with 11.2 liters of Cl2 (which is also 1 mole at STP), the mole of HCl gas formed will be equal to 1 mole.

Energy density and Young's modulus have the same dimensions. Energy density is the amount of energy stored in a given volume, and its dimensions are energy divided by volume. Young's modulus is a measure of the stiffness of a material, and its dimensions are force divided by area. Both of these parameters have dimensions of energy divided by volume, so they have the same dimensions.

Radioactive dating is a method used to determine the age of rocks and fossils by measuring the decay of radioactive isotopes. The given answer, 1017 s, represents a very long time interval of approximately 10 quintillion (10^17) seconds. This is an appropriate timescale for radioactive dating because it allows for the measurement of the decay of isotopes with long half-lives, such as uranium-238 and potassium-40, which can be used to date rocks that are millions or billions of years old.