The question asks about the primary application of mica. To answer this, we need to recall the key properties of mica and how they make it suitable for specific industrial uses.
Correct Option: B) electric industry
Mica is widely used in the electric and electronic industries due to its excellent dielectric strength, high heat resistance, and chemical stability. It serves as an insulator in capacitors, heating elements, and various electrical appliances. Its ability to withstand high voltages and temperatures makes it indispensable for these applications.
The question asks about the deficiency that causes goitre in the human body. Goitre is a condition characterized by the enlargement of the thyroid gland. Understanding the role of various elements in thyroid hormone production is key to answering this question.
A) Iodine — Iodine is an essential trace element required for the synthesis of thyroid hormones. A deficiency of iodine leads to insufficient production of these hormones, prompting the thyroid gland to enlarge in an attempt to capture more iodine, resulting in goitre.
The question asks to identify the instrument used for measuring electric current. We need to recall the functions of the given instruments.
Correct Option: C) Ammeter is the instrument specifically designed to measure electric current.
The question asks about the energy source for automatic wristwatches. Automatic watches are mechanical watches that do not require a battery. They are self-winding, meaning they generate their own power from the wearer's movements.
D) movement of our hands. This option accurately describes how automatic wristwatches get their energy. The kinetic energy generated by the movement of the wearer's hand causes a rotor inside the watch to spin, which then winds the mainspring.
The question asks to identify the author of the historical work "Akbarnama". This requires knowledge of prominent historians and literary figures during the Mughal period, specifically Emperor Akbar's reign.
Correct Option: C) Abul Fazal wrote the "Akbarnama". It is a three-volume official history of the reign of Akbar, commissioned by Akbar himself. The first volume deals with Akbar's ancestors, the second with Akbar's reign up to the 46th regnal year (1601–1602), and the third volume is known as "Ain-i-Akbari", which details the administrative system of the empire.
This question tests basic knowledge about the speed of light and sound. When a television is switched on, both audio and visual signals are processed. The key to answering this question lies in understanding the relative speeds at which light (which carries the visual information) and sound (which carries the audio information) travel.
A) We listen to the sound first and then see the picture
This is often the case, particularly in older televisions or due to the simpler processing required for audio compared to video. While modern TVs strive for perfect synchronization, if there's a slight delay, the audio often becomes perceptible first. This is a common observation and a design characteristic in many TV systems.
The question asks to identify the country with the largest number of post offices as of 2018. This is a factual question requiring knowledge of global postal statistics.
India Post, established in 1854, has historically maintained one of the largest and most widespread postal networks in the world. Its vast network is crucial for connectivity, especially in rural areas.
As of 2018, and even currently, India holds the distinction of having the largest postal network in the world with over 1.5 lakh (150,000) post offices. Approximately 89% of these are in rural areas.
C) India — India has the largest postal network in the world, with over 150,000 post offices as of 2018. This extensive network is vital for communication and financial services across its vast geography.
The question asks to identify the Indian state with the longest coastline. This requires knowledge of the geographical features of Indian states, specifically the length of their coastlines.
The approximate coastline lengths of the given states are:
Comparing these values, Gujarat clearly has the longest coastline among the given options, and indeed, among all Indian states on the mainland.
B) Gujarat has the longest coastline among all Indian states, primarily due to its highly indented shape and the presence of the Gulf of Kutch and Gulf of Khambhat.
This problem involves comparing the kinetic energies of two objects with different masses but the same momentum. We need to use the formulas for momentum and kinetic energy and establish a relationship between them to determine how kinetic energy depends on mass when momentum is constant.
Define Momentum and Kinetic Energy:
Express Kinetic Energy in terms of Momentum:
From the momentum equation, we can express velocity as \(v = \frac{p}{m}\). Substitute this into the kinetic energy equation:
\[ KE = \frac{1}{2} m \left( \frac{p}{m} \right)^2 \] \[ KE = \frac{1}{2} m \frac{p^2}{m^2} \] \[ KE = \frac{p^2}{2m} \]Compare Kinetic Energies for Unequal Masses with Same Momentum:
Let \(m_1\) be the mass of the heavier object and \(m_2\) be the mass of the lighter object. So, \(m_1 > m_2\).
Let \(KE_1\) be the kinetic energy of the heavier mass and \(KE_2\) be the kinetic energy of the lighter mass.
Since both masses have the same momentum (\(p\)), we can write:
\[ KE_1 = \frac{p^2}{2m_1} \] \[ KE_2 = \frac{p^2}{2m_2} \]Determine the Relationship:
We know that \(m_1 > m_2\). Since \(p^2\) and \(2\) are positive constants, the kinetic energy is inversely proportional to the mass when momentum is constant. That is, \(KE \propto \frac{1}{m}\).
Therefore, if \(m_1 > m_2\), then \[\frac{1}{m_1} < \frac{1}{m_2}\].
This implies that \(KE_1 < KE_2\).
So, the kinetic energy of the heavier mass is smaller than the kinetic energy of the lighter mass.
A) smaller than. As derived, when momentum is constant, kinetic energy is inversely proportional to mass. Therefore, the heavier mass will have smaller kinetic energy compared to the lighter mass.
The question asks for the capital city of Maharaja Ranjit Singh's kingdom. This is a factual question related to Indian history, specifically the Sikh Empire.
Correct Option: C) Lahore was the capital of Ranjit Singh's kingdom, the Sikh Empire.