Question Discussion & Solution

The correct answer is First.

• As of June 2015, First place does Rajasthan have in solar power generation between Indian states.

• Solar power capacity of Rajasthan
  • ​According to data released by the Union ministry of new and renewable energy on June 4, 2015, Rajasthan has grabbed the number one position in the country with an installed capacity of 1,167 megawatts against Gujarat's 1,000 MW.

Additional Information

Solar power capacity of India: ​Top 5 states

The correct answer is Concave.

Key Points

• Concave Mirror:-
  • If a hollow sphere is cut into parts and the outer surface of the cut part is painted, then it becomes a mirror with its inner surface as the reflecting surface.
  • This type of mirror is known as a concave mirror.
  • A concave mirror has a reflective surface that is curved inward and away from the light source.
  • Concave mirrors reflect light inward to one focal point.
  • Unlike convex mirrors, the image formed by a concave mirror shows different image types depending on the distance between the object and the mirror.
  • Torch lights, automobile headlights are examples of concave mirrors.
  • The mirror used by the dentists to see the teeth of the patients is also a Concave Mirror.
  • Uses of Concave Mirror:
  • Used in shaving mirrors, ophthalmoscope, astronomical telescopes, headlights, solar furnaces.

Additional Information

• Convex Mirror:-
  • If the cut part of the hollow sphere is painted from inside, then its outer surface becomes the reflecting surface.
  • This kind of mirror is known as a convex mirror.
  • A convex mirror is also known as a diverging mirror as this mirror diverges light when they strike its reflecting surface.
  • Virtual, erect, and diminished images are always formed with convex mirrors, irrespective of the distance between the object and the mirror.
  • A convex mirror is a diverging mirror in which the reflective surface bulges towards the light source.
  • They are not used to focus light as they reflect light outwards.
  • The image formed by convex mirrors is smaller than the object but gets larger as they approach the mirror.
  • Magnifying glasses, telescopes are examples of convex mirrors.
  • Uses of Convex Mirror: Inside buildings, Vehicle mirrors, Magnifying glass, Security purposes.
• Plane Mirror:-
  • A plane mirror is a flat, smooth reflective surface.
  • A plane mirror always forms a virtual image that is upright, and of the same shape and size as the object, it is reflecting.
  • A spherical mirror is a mirror that has a consistent curve and a constant radius of curvature.
  • The images formed by a spherical mirror can either be real or virtual.
  • Spherical mirrors are of two types:
    • Concave Mirror
    • Convex Mirror
  • Uses of Plane Mirror: Solar cookers, looking glass, scientific instruments, constructing periscope which is used in submarines, kaleidoscope, a toy which produces beautiful patterns, SLR camera to click photos.

The correct answer is about 70% water.

Important Points

• The Top Four Elements Found in the Human Body: oxygen (65%), carbon (18.5%), hydrogen (9.5%), nitrogen (3.2%).
• The other trace elements (less than 0.01%) are boron (B), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), fluorine (F), iodine (I), iron (Fe), manganese (Mn), molybdenum (Mo), selenium (Se), silicon (Si), tin (Sn), vanadium (V), and zinc (Zn).
• The six major nutrients are carbohydrates (CHO), lipids (fats), proteins, vitamins, minerals, water.
• The functions of water in the human body:
  • Water carries nutrients and oxygen to all cells in the body.
  • Water is required for breathing.
  • Water regulates your body temperature.
  • Water protects and cushions vital organs.
  • Water cushions joints.
  • Water removes waste.

Key Points

• Calcium (Ca) is the most abundant mineral in the body and is essential for a number of vital functions.
  • Also helps muscles relax and contract, important in nerve functioning, blood clotting, blood pressure regulation, immune system health.
• Iron (Fe), Part of a molecule (haemoglobin) found in red blood cells that carries oxygen in the body, needed for energy metabolism.
• Iodine found in thyroid hormone, which helps regulate growth, development, and metabolism.
• Chromium works closely with insulin to regulate blood sugar (glucose) levels.

Pack is a group of Wolves.

Similarly,

Concept:

​Simple Pendulum:

• A simple pendulum consists of a small metallic ball or a piece of stone suspended from a rigid stand by a thread.
  The metallic ball is called Bob.
• A pendulum swings from one extreme position to another and comes back to the same position, this completes one oscillation. 
• One oscillation can also be defined as the pendulum starting from the mean position, going to one extreme, and coming back to the same mean position. 
• The time duration to compete for one oscillation is called time period and the is reciprocal of time period is frequency. 
• Frequency: The number of oscillations per unit time is called frequency. 

\(frequncy =\frac{Oscillation}{Time}\)

Calculation:

Given that : Frequency = 2 hz and time = 16 sec.

In a sec pendulum completes 2 oscillations per second.

⇒ Oscillations = Frequency × time

⇒ Oscillations = 2×16

⇒ Oscillations = 32

Additional Information

The time period of a simple pendulum depends upon on the length of the string and acceleration due to gravity.

\(T = 2 \pi \sqrt{\frac{l}{g}}\)

l is length, g is acceleration due to gravity.