This is a direction-based reasoning question. We need to determine Mamata's facing direction based on Nandini's orientation relative to the sunrise.
Correct Option: D) West
The question asks to identify the Governor of the Reserve Bank of India (RBI) as of 2018. This requires knowledge of the history of RBI governorships.
Correct Option: C) Urjit Patel
The problem asks us to find a number such that 20% of 50 is equal to 25% of that number. We can solve this by first calculating 20% of 50 and then setting up an equation to find the unknown number.
Calculate 20% of 50:
To find a percentage of a number, we convert the percentage to a decimal or a fraction and multiply it by the number.
\[ 20\% \text{ of } 50 = \frac{20}{100} \times 50 \]\[ = \frac{1}{5} \times 50 \]\[ = 10 \]Set up the equation:
Let the unknown number be \(x\). The problem states that 20% of 50 is 25% of \(x\). From step 1, we know 20% of 50 is 10. So, we can write the equation:
\[ 10 = 25\% \text{ of } x \]\[ 10 = \frac{25}{100} \times x \]\[ 10 = \frac{1}{4} \times x \]Solve for \(x\):
To find \(x\), multiply both sides of the equation by 4:
\[ 10 \times 4 = x \]\[ x = 40 \]Verify the answer:
If \(x = 40\), then 25% of 40 is:
\[ 25\% \text{ of } 40 = \frac{25}{100} \times 40 \]\[ = \frac{1}{4} \times 40 \]\[ = 10 \]Since 20% of 50 is 10, and 25% of 40 is also 10, the unknown number is 40.
D) 40 — As calculated, 20% of 50 is 10, and 25% of 40 is also 10. Thus, the equality holds true for 40.
The question asks for the standard unit of frequency for a sound wave. We need to recall the definitions and units of various physical quantities related to waves and sound.
D) hertz is the correct answer. The hertz (Hz) is the SI unit for frequency, defined as one cycle per second (\(1 \, \text{Hz} = 1 \, \text{s}^{-1}\)).
The question asks for the venue of the Hockey Men's World Cup 2018. This is a factual question related to sports events and their locations. To answer correctly, one needs to recall the host city for this specific international tournament.
Correct Option: A) Bhubaneswar was the host city for the Hockey Men's World Cup 2018.
The question asks to identify the recipient of the 2018 Santokbaa Humanitarian Award. This requires knowledge of prominent awards and their recipients, a common topic in general awareness sections of competitive exams.
Correct Option: C) Kailash Satyarthi
Kailash Satyarthi, a Nobel Peace Prize laureate, was honored with the 2018 Santokbaa Humanitarian Award for his exceptional contributions to humanitarian causes, particularly his efforts in advocating for children's rights and combating child labor globally.
The question asks for the commercial unit of electrical energy. This refers to the unit commonly used by electricity providers to bill consumers for the energy they consume. We need to identify which of the given options represents a unit of energy and is used commercially.
Correct Option: A) Kilowatt-hour is the commercial unit of electrical energy. It represents the energy consumed by a device with a power of 1 kilowatt operating for 1 hour. It can be converted to Joules: \[ 1 \text{ kWh} = 1 \text{ kW} \times 1 \text{ h} = 1000 \text{ W} \times 3600 \text{ s} = 3.6 \times 10^6 \text{ J} \] This large value demonstrates why it's a practical unit for commercial use.
How many triangles are there in the following figure?
To determine the number of triangles in the given figure, we need to carefully count each triangle formed by the intersecting lines. The figure consists of multiple smaller triangles and some larger ones formed by combining these smaller triangles.
Thus, the total number of triangles is \(8 + 4 + 1 = 13\).
Correct Option: C) 12
To determine which substance has the highest melting and boiling point, we need to consider the type of bonding and structure present in each element. Stronger intermolecular or interatomic forces lead to higher melting and boiling points.
C) Carbon has a giant covalent network structure (e.g., diamond, graphite) where each carbon atom is covalently bonded to several other carbon atoms throughout the entire structure. These strong, extensive covalent bonds require a tremendous amount of energy to break, resulting in exceptionally high melting and boiling points (e.g., diamond sublimes at around \(3800^\circ C\)).
Acidity is caused by an excess of acid in the stomach. To relieve this, a substance that can neutralize the acid is needed. This substance should be a base or an antacid.
Correct Option: A) baking soda solution
Baking soda, chemically known as sodium bicarbonate (\(\text{NaHCO}_3\)), is a mild base. When consumed as a solution, it reacts with the excess hydrochloric acid in the stomach to neutralize it, providing relief from acidity. The reaction is:
\[\text{HCl (acid)} + \text{NaHCO}_3 \text{ (base)} \rightarrow \text{NaCl (salt)} + \text{H}_2\text{O (water)} + \text{CO}_2 \text{ (carbon dioxide)}\]