The question asks for the real name of Sher Shah Suri, also known as Sher Khan. This is a direct factual recall question from Indian history, specifically related to the Sur Empire.
Correct Option: A) Farid was the real name of Sher Shah Suri.
The question asks about the current-voltage (I-V) graph for ohmic devices. This requires understanding Ohm's Law and how it relates current, voltage, and resistance, and then visualizing this relationship graphically.
D) Linear curve — As derived from Ohm's Law (\(I = \frac{1}{R} V\)), the relationship between current and voltage for an ohmic device is directly proportional, resulting in a straight line (linear curve) when plotted on a graph.
Morris used to spend 25% of his income on food. He got an increment of one thousand rupees, but he did not increase his expenditure on food items. As a result, his expenditure on food fell to 20%. What was his initial income?
This problem involves calculating initial income based on percentage expenditure on food before and after an income increment. We can set up equations based on the given percentages and the constant expenditure on food to find the initial income.
Let the initial income be \(I\).
Initially, Morris spent 25% of his income on food. So, the expenditure on food (\(E_F\)) was:
\[ E_F = 0.25 \times I \]He received an increment of Rs. 1,000. So, his new income (\(I'\)) is:
\[ I' = I + 1000 \]He did not increase his expenditure on food items, meaning the food expenditure remained \(E_F\).
As a result, his expenditure on food fell to 20% of his new income. So, we can write:
\[ E_F = 0.20 \times I' \] \[ E_F = 0.20 \times (I + 1000) \]Now we have two expressions for \(E_F\). We can equate them:
\[ 0.25 \times I = 0.20 \times (I + 1000) \]Solve the equation for \(I\):
\[ 0.25I = 0.20I + 0.20 \times 1000 \] \[ 0.25I = 0.20I + 200 \] \[ 0.25I - 0.20I = 200 \] \[ 0.05I = 200 \] \[ I = \frac{200}{0.05} \] \[ I = \frac{200}{\frac{5}{100}} \] \[ I = 200 \times \frac{100}{5} \] \[ I = 40 \times 100 \] \[ I = 4000 \]So, his initial income was Rs. 4,000.
D) Rs. 4,000 — The calculation shows that the initial income was Rs. 4,000. Let's verify: Initial income = Rs. 4,000. Food expenditure = 25% of 4,000 = Rs. 1,000. New income = 4,000 + 1,000 = Rs. 5,000. Food expenditure (Rs. 1,000) is 20% of new income (Rs. 5,000), which is correct (1000/5000 = 0.20 = 20%).
To divide an amount in a given ratio, we first find the sum of the ratio parts. Then, we determine the fraction of the total amount that each person receives by dividing their respective ratio part by the sum of the ratio parts. Finally, we multiply this fraction by the total amount to find each person's share.
A) Rs. 40 is the correct amount Jayati received based on the given ratio.
The question asks to identify the classification system that features 7 periods and 18 groups. We need to recall the characteristics of the different periodic classifications mentioned in the options.
Correct Option: B) Modern periodic table
The question asks about the primary mineral for which the Jadugoda mines are famous. This requires knowledge of important mining locations in India and their associated minerals.
Correct Option: A) Uranium — The Jadugoda mines are renowned for being India's first uranium mine and a major source of uranium ore for the country's nuclear power program.
The question asks to identify the lightest metal among the given options. This requires knowledge of the periodic table and the properties of elements, specifically their atomic mass and classification as metals or non-metals.
Correct Option: B) Li (Lithium) is an alkali metal with the lowest atomic mass among all metals, making it the lightest metal.
Which of the following oxides is a major component of cement?
The question asks to identify a major component of cement from the given options. Cement is a complex mixture of various oxides, and understanding the primary constituents is key to answering this question.
C) \(\text{SiO}_2\) (Silicon dioxide or silica) is a major component of cement, typically constituting 17-25% of its mass. It reacts with calcium oxide during the clinkering process to form calcium silicates, which are responsible for the strength of hardened cement.
The group number of an element in the modern periodic table is determined by the number of valence electrons (electrons in the outermost shell) for main group elements. For elements with 8 valence electrons (except Helium), they belong to Group 18, also known as the noble gases.
Correct Option: C) 18 — An element with 8 valence electrons (and more than one shell) is a noble gas and belongs to Group 18 of the modern periodic table.
The question asks for the term that describes the change in the speed of light when it moves from one medium to a denser one. This phenomenon is known as refraction, and the extent of this change is quantified by a specific optical property of the medium.
B) Refractive index is the correct answer because it quantifies the change in the speed of light when it enters a different medium. A higher refractive index indicates a greater reduction in the speed of light within that medium.