# UKPCS Answer writing practice S&T#25

The most important and most neglected part for Civil Services Preparation is answer writing. It is not about HOW MUCH YOU STUDY but CAN YOU WRITE within word limit and time frame. After UPPCS daily answer writing practice, ORACLE IAS comes out with new initiative UKPCS DAILY ANSWER WRITING PRACTICE.)

###### विद्युत धारा क्या है? विभिन्न प्रकार की विद्युत धारा में अंतर बताएं और उनके उपयोग भी लिखें|

1. The International Solar Alliance (ISA) is an alliance of more than 121 countries, most of them being sunshine countries, which lie either completely or partly between the Tropic of Cancer and the Tropic of Capricorn. Countries that do not fall within the Tropics can join the alliance and enjoy all benefits as other members, with the exception of voting rights. It is to be headquartered in India in Gurugram.

There are three objectives behind the International Solar Alliance.

1. To force down prices of solar technology by driving demand.
2. To bring standardization in the manufacturing of the solar panels and other solar technologies, so that the prices can fall substantially.
3. To foster research and development in solar technology.

1. An electric current is a flow of electric charge. In electric circuits this charge is often carried by moving electrons in a wire. It can also be carried by ions in an electrolyte, or by both ions and electrons such as in an ionised gas. Current flows from negative to positive points. The SI unit for measuring electric current is the ampere (A).

The main Difference between AC and DC is discusses in the following chart:

 Characteristic Alternating Current Direct Current The amount of energy that can be carried It is safe to transfer over longer city distances and will provide more power. Practically the voltage of DC cannot travel very far until it begins to lose energy. The cause of the direction of flow of electrons It is denoted rotating magnet along the wire. It is denoted steady magnetism along the wire Frequency The frequency of alternating current will be either 50Hz or 60Hz depending upon the country. The frequency of direct current will be zero. Direction It reverses its direction while flowing in a circuit. It only flows in one direction in the circuit. Current It is the current of magnitude which is varying with time It is the current of constant magnitude. Flow of Electrons Here electrons will keep switching the directions – forward and backward. Electrons move steadily in one direction or ‘forward’. Obtained from The source of availability is A.C Generator and mains. The source of availability is either Cell or Battery. Passive Parameters It is Impedance. Only Resistance Power Factor It basically Lies between 0 & 1. It will be always 1. Types It will of different types like Sinusoidal, Square Trapezoidal, and Triangular. It will be of Pure and pulsating.

Application of AC:

• AC permits efficient transmission of power (Grid System)
• AC presents a convenient way to share and convert different energies
• AC provides inherent mechanism for synchronizing multiple sources.

DC is most commonly produced by sources such as solar cells, batteries, and thermocouples. DC power is widely used in low voltage applications such as charging batteries, automotive applications, aircraft applications and other low voltage, low current applications.