Relation between electric field and potential

According to the relation between electric field and potential,

• Electric field is in the direction in which the potential decreases steepest.
• Its magnitude is given by the change in the magnitude of potential per unit displacement normal to the equipotential surface at the point.

The bangle-makers lead their life in utter miseries and grinding poverty. They could never prosper working in this industry. In her lesson, the writer points out that the bangle-makers of Firozabad live in the state of grinding poverty. These people are burdened the stigma of caste in which they are born. Following are the difficulties, faced by the bangle makers of Firozabad : They work in the dingy cells without air and light. They work in high temperatures in front of hot furnaces. Dust from polishing bangles affect their eyes and sometimes causes blindness.

While describing the pitiable condition of the slum school children in Tyrol Valley, Spender points out that their slum dwellings are their narrow confines of foggy existence. They are devoid of education. The map on the wall, picture of Shakespeare and other gifts are meant for their temptation. They will urge them to steal rather than pave way to progress and education.

William Douglas developed an aversion to water when he was three or four years old. He stood at a beach with his father when a wave Swept over him and knocked him down. He was buried under water and became breathless. He was petrified and developed a permanent fear for water.

Gandhiji demanded 50% refund from the British landlords in the form of repayment of money which the landlords had illegally and deceitfully extorted from the poor sharecroppers. Question 8. Answer: Gandhiji had asked the indigo planters for a 50 percent refund to the farmers but they offered only 25 percent.

Likewise, what was the long term contract between the sharecroppers and English landlords? The British landlords had entered into a long-term contract with the farmers according to which they compelled all tenants to plant 15% of their holdings with indigo. The sharecroppers had to surrender the entire indigo harvest as rent. Answer.

Also to know is, what was the condition of indigo sharecroppers?

The main problem of sharecroppers in Champaran was that all the tenants were forced and compelled to plant 15% of their holdings with Indigo. This has been a long-term contract between the British and the farmers. The sharecroppers, on the other hand, had to hand over the entire Indigo harvest as rent to the British.

Solids can very easily be distinguished from liquids by their definite shape, considerable mechanical strength, and rigidity. There are many different types of solids. Some are soft and others are hard. Some are rigid and others are flexible. The atoms and molecules of solids are held together by pulling forces called bonds. 

The atoms in solids are held together by interatomic forces. The average location of the atoms in a lattice does not change with time. Since the atoms are almost lacking in mobility, their kinetic energy is negligibly small. It is this lack of mobility which makes a solid rigid.

Electric current flowing through a conductor I = n AqV_d

where A = cross-sectional area of the conductor, n=  number of conduction electrons per unit volume, q is the charge of an electron and V_d is the drift velocity.

Van de Graaff generator is a device used for building up high potential differences of the order of a few million volts.

Principle − It is based on the principle that charge given a hollow conductor is transferred to the outer surface and is distributed uniformly over it.

Construction:

It consists of a large spherical conducting shell (S) supported over the insulating pillars. A long narrow belt of insulating material is wound around two pulleys P₁ and P₂. B₁ and B₂ are two sharply pointed metal combs. B₁ is called the spray comb and B₂ is called the collecting comb.

Working − The spray comb is given a positive potential by a high tension source. The positive charge gets sprayed on the belt.
As the belt moves and reaches the sphere, a negative charge is induced on the sharp ends of the collecting comb B₂ and an equal positive charge is induced on the farther end of B₂.
This positive charge shifts immediately to the outer surface of S. Due to discharging action of sharp points of B₂, the positive charge on the belt is neutralised. The uncharged belt returns downwards and collects the positive charge from B₁, which in turn is collected by B₂. This process is repeated and the positive charge on S goes on accumulating. In this way, voltage differences of as much as 6 or 8 million volts (with respect to the ground) can be built up

Use: Van de Graaff generator generates high potential differences that are used to accelerate charged particles such as electrons, protons, ions, etc. used for nuclear disintegration.

Limitations: 1) It's a series combination that allows only one route for the movement of charge.

2) It can accelerate only the charged particles not the uncharged particles.

Functions of a Central Bank. Main functions of a Central Bank are to act as governor of the machinery of credit in order to secure stability of prices. It regulates the volume of credit and currency, pumping in more money when market is dry of cash, and pumping out money when there is excess of credit. Broadly, a central bank has two departments, namely, issue department and banking department. We discuss below its main functions.

1.    Issue of Currency. The central bank is given the sole monopoly of issuing currency in order to secure control over volume of currency and credit. These notes circulate throughout the country as legal tender money. Note-issuing is governed by Minimum Reserve System i.e. while issuing currency notes, a minimum fixed amount of gold and foreign currency is kept by Central Bank. It has to keep a reserve in the form of gold and foreign securities as per statutory rules against the notes issued by it. It may be noted that RBI issues all currency notes in India except one rupee note. Again it is under directions of RBI that one rupee notes and small coins are issued by government mints. Remember, central government of a country is usually authorised to borrow money from the central bank. When central government expenditure exceeds government revenue and Govt, is unable to reduce its expenditure, then it borrows from RBI. This is done by selling security bills to RBI which creates new currency notes for the purpose. This is called monetisation of budget deficit or deficit financing. The government spends new currency and puts it into circulation to meet its expenditure.

2.    Banker to the Government. Central Bank functions as a banker to the government— both central and state governments. It carries out all banking business of the government. Governments keep their cash balances in the current account with the central bank. Similarly, central bank accepts receipts and makes payment on behalf of the governments. Also central bank carries out exchange, remittance and other banking operations on behalf of the government. Central bank gives loans and advances to governments for temporary periods, as and when necessary, and it also manages the public debt of the country.

3.    Bankers’ Bank and Supervisor. There are usually hundreds of banks in a country. There should be some agency to regulate and supervise their proper functioning. This duty is discharged by the central bank. Central bank acts as banker's bank in three capacities : (i) it is custodian of their cash reserves. Banks of the country are required to keep a certain percentage of their deposits with the central bank; and in this way the central bank is the ultimate holder of the cash reserves of commercial banks. (ii) Central bank is lender of last resort. Whenever banks are short of funds, they can take loans from the central bank and get their trade bills discounted. Thus Central Bank is a source of great strength to the banking system. (iii) It acts as a bank of central clearance, settlements and transfers. Its moral persuasion is usually very effective so far as commercial banks are concerned.

In his last French class though M. Hamel was emotional he fully involved himself in the teaching-learning process. He heard every lesson to the last sitting motionless in the chair. When the church bell struck twelve he stood up pale and wrote ‘Vive La France’ and with a gesture, he communicated that the school is dismissed.