This question asks about the relationship between temperature and the electrical resistance of most conductors. We need to recall the fundamental principles of electrical conductivity in metals and how temperature affects the movement of charge carriers and lattice vibrations.
Correct Option: A) It increases. As the temperature of most conductors increases, the thermal vibrations of their atoms become more vigorous, leading to more frequent collisions with the free electrons. This increased scattering of electrons impedes their flow, thereby increasing the electrical resistance.
The question asks to identify the environmental advantage of a paper cup over a plastic cup. This requires understanding the material properties of both and their impact on the environment, particularly regarding waste management and decomposition.
Correct Option: D) Biodegradable — Paper cups are made from natural fibers (cellulose) which can be broken down by microorganisms in the environment. This means they decompose relatively quickly compared to plastic, reducing landfill burden and environmental pollution. This attribute makes them a more environmentally friendly choice than plastic cups.
₹5,400 were divided among P, Q and R, such that 6 times of P = 3 times of Q = 8 times of R. Find the share of R.
The problem involves dividing a total sum of money among three individuals (P, Q, and R) based on a given relationship between their shares. The relationship is expressed as an equality involving multiples of their shares. The key is to convert this relationship into a ratio of their shares and then use this ratio to find each person's individual share from the total amount.
Understand the given relationship:
We are given that 6 times the share of P is equal to 3 times the share of Q, which is also equal to 8 times the share of R. Let P, Q, and R denote their respective shares. So, we have the equation:
Find the ratio P : Q : R:
To find the ratio, we can set each part of the equality to a constant, say \(k\).
So, \(6P = k \implies P = \frac{k}{6}\)
\(3Q = k \implies Q = \frac{k}{3}\)
\(8R = k \implies R = \frac{k}{8}\)
Therefore, the ratio \(P : Q : R\) is:
Convert the fractional ratio to a whole number ratio:
To convert this fractional ratio to a whole number ratio, we find the Least Common Multiple (LCM) of the denominators (6, 3, 8).
LCM of 6, 3, 8 is 24.
Multiply each term in the ratio by the LCM (24):
Calculate the sum of the ratio parts:
The sum of the ratio parts is \(4 + 8 + 3 = 15\).
Calculate the share of R:
The total amount to be divided is ₹5,400. The share of R is the ratio part of R divided by the sum of the ratio parts, multiplied by the total amount.
D) ₹1,080 is the correct share for R, as calculated by converting the given relationship into a ratio and then distributing the total amount.
By selling an article at \( \frac{5}{14} \) of its actual selling price, Hitesh incurs a loss of 20%. If he sells it at 80% of its actual selling price, then the profit percentage is:
We need to find the profit percentage when an article is sold at 80% of its actual selling price, given that selling it at \( \frac{5}{14} \) of its actual selling price results in a 20% loss. We will establish relationships between Cost Price (CP), Actual Selling Price (ASP), and the selling prices under two different scenarios.
Correct Option: D) 79.2%
To evaluate the given expression, we need to follow the order of operations, commonly remembered by the acronym PEMDAS/BODMAS. This stands for Parentheses/Brackets, Exponents/Orders, Multiplication and Division (from left to right), and Addition and Subtraction (from left to right).
Thus, the value of the expression is 3.
A) 3 — The calculation following the correct order of operations (BODMAS/PEMDAS) leads to the result 3.
A precipitation reaction is a type of double displacement reaction where two soluble ionic compounds react in an aqueous solution to form an insoluble product called a precipitate. We need to identify the reaction among the given options that produces an insoluble solid.
D) NaCl + AgNO₃ → NaNO₃ + AgCl — This reaction involves the mixing of two soluble ionic compounds, sodium chloride and silver nitrate, in an aqueous solution. The products formed are sodium nitrate, which is soluble, and silver chloride (AgCl), which is an insoluble solid. The formation of this insoluble solid (precipitate) makes it a precipitation reaction.
The question asks for the best description of the climate of the Thar Desert. To answer this, one needs to recall the characteristic features of desert climates.
Correct Option: D) arid
The question asks for the primary reason behind the global manufacturing shift towards CFC-free refrigerators. This requires knowledge of the environmental impact of CFCs.
A) CFC is a synthetic chemical which depletes the ozone layer. This is the correct reason. Chlorofluorocarbons (CFCs) were widely used as refrigerants and propellants. However, it was discovered that when released into the atmosphere, CFCs rise to the stratosphere and break down ozone molecules. The ozone layer protects Earth from harmful ultraviolet (UV) radiation. Its depletion leads to increased UV radiation reaching the Earth's surface, causing health problems like skin cancer and cataracts, and harming ecosystems. This environmental threat led to international agreements like the Montreal Protocol to phase out CFC production and use, thus prompting the manufacturing of CFC-free refrigerators worldwide.
To solve this blood relation problem, we will systematically trace the relationships given in the statements to build a family tree or a chain of relations. We will then determine the relationship between B and E based on this chain.
A) Father's father
As derived in the step-by-step explanation, B is the father of C, and C is the father of E. Therefore, B is E's father's father (paternal grandfather).
To find the average speed, we need to calculate the total distance traveled and the total time taken. Average speed is defined as the total distance divided by the total time.
Correct Option: A) 31