It fails to explain the acidic nature of substances like CO₂, SO₂,SO₃ etc which do not have hydrogen and similarly it also fails to explain the basic nature of substances like NH₃, CaO, MgO etc which do not have -OH group.

It fails to explain the acidic and basic behaviour of substances in solvents other than water such as ammonia,alcohol.etc

The theory fails to explain why strong electrolytes like nitric acid (HNO₃) are completely ionized in aqueous solution whereas weak electrolytes like acetic acid (CH₃COOH) are ionized to a small extent only.

• Magnetic Field due to a Current carrying Conductor:

Magnetic Field due to a Straight Current-carrying Conductor:

The magnetic field lines around a straight conductor carrying a current are concentric circles.

The direction of a magnetic field is given by the Right-Hand Thumb Rule.

Right-Hand Thumb Rule:

Imagine that you are holding a straight current-carrying conductor in your right hand such that the thumb points towards the direction of the current. Then, your curved fingers wrapped around the conductor point in the direction of the field lines of the magnetic field.

The magnitude of the magnetic field due to a straight current-carrying conductor at a given point is

1. Directly proportional to the current flowing through the conductor.
2. Inversely proportional to the distance of that point from the conductor.

Magnetic Field due to a Current-carrying Circular Coil:

1. The magnetic field lines near the coil are nearly circular or concentric.
2. The magnetic field at the centre of the coil is maximum and almost uniform.
3. Looking at the face of a coil, if the current around it is in the clockwise direction, then it faces the South Pole. If the current around it is in the anticlockwise direction, then it faces the North Pole. This is called the Clock rule.
4. The magnitude of a magnetic field at the centre of the coil is

1. Directly proportional to the current flowing through it
2. Inversely proportional to the radius of the coil
3. Directly proportional to the number of turns of the coil

Magnetic Field due to a Current-carrying Solenoid:

Solenoid is a long coil containing a large number of close turns of insulated copper wire. The magnetic field produced by passing the current through the coil. Magnetic field produced by the solenoid is similar to the magnetic field produced by the bar magnet. The magnetic field lines in the solenoid are parallel.

The magnetic field inside a solenoid is uniform.

In  accordance  with  the Clock  rule,  the  end  of  the  solenoid  at  which  the  current  flows in  the anticlockwise direction behaves  as  a North Pole,  while  the  end  at  which  the  current  flows in  the clockwise direction behaves as a South Pole.

The magnitude of the magnetic field inside the solenoid is directly proportional to the

1. Current flowing through it
2. Number of turns per unit length of the solenoid

Electric potential is the work done per unit charge in bringing the charge from infinity to that point against electrostatic force.

In a conductor, electrons flow only when there is a difference in electric pressure at its ends. This is also called potential difference. In a circuit, this potential difference is created by a battery.

The story starts when Mrs. Pumphrey, a rich lady takes her dog out for a walk. A nearby veterinary doctor who knows the lady sees the dog and is shocked as he sees that the dog looks like a bloated sausage with a leg at each end. He advises her to stop giving him unhealthy things to eat but Mrs. Pumphrey is not able to refuse him. Soon he falls sick and the doctor is called. The narrator, Mr. Herriot then somehow takes Tricki, the dog to the hospital even though he knows that Mrs. Pumphrey is not ready to leave her dog and nearly fainted just by hearing these words.Then he takes the dog along and puts a bed for him in his surgery. The dog doesn't move much nor eats anything for the first two days. On the second day he looks around and whimpers a bit. He wanted to go out on the third day and started playing with the bigger dogs when he was taken out. He also licked the bowls of other dogs clean on the third day.

Then his condition started improving very fast. He started fighting for his meals with other dogs. Then when this news reached Mrs. Pumphrey, she started sending him eggs as she thought that Tricki was recovering from an illness and needed energy foods. Mr. Herriot and his partners started eating those eggs for morning breakfast. Then for improving Tricki’s blood, Mrs. Pumphrey started sending in bottles of wine which was again consumed by Mr. Herriot. He used to take two glasses before lunch and some more glasses while having his lunch. Then when she started sending in bottles of brandy for Tricki that was the time when Mr. Herriot thought that he would really like to keep Tricki as a permanent guest in the surgery. Mr. Herriot used to be really happy someday by having two extra eggs every morning. Then having few glasses of wine in the afternoon and closing the day by having brandy at night. But then he took a wise decision and called up Mrs. Pumphrey as she was really worried and on this side Tricki was ready to be taken back home. Tricki was really happy to see his mistress and jumped into the car. Mrs. Pumphrey said that she won't be able to ever thank him for what he had done and also, that his surgery had been successful as Tricki was now cured.

Land resources are used for the following purposes:

(i)Forests

(ii)Land not available for cultivation: 

(a) Barren and waste land

(b) Land put to non-agricultural uses, e.g. buildings, roads, factories, etc.

(iii)Other uncultivated land (excluding fallow land): 

(a) Permanent pastures and grazing land,

(b) Land under miscellaneous tree crops groves (not included in net sown area),

(c) Cultruable waste land (left uncultivated for more than 5 agricultural years).

(iv)Fallow lands: 

(a) Current fallow-(left without cultivation for one or less than one agricultural year),

(b) Other than current fallow-(left uncultivated for the past 1 to 5 agricultural years).

(v)Net sown area: 

Area sown more than once in an agricultural year plus net sown area is known as gross cropped area.

'Red shift' is a key concept for astronomers. The term can be understood literally - the wavelength of the light is stretched, so the light is seen as 'shifted' towards the red part of the spectrum.

Cutting:A small part of a plant which is removed by making a cut with a sharp knife is called cutting.A cutting of parent plant having some bud on it is taken and its lower part is buried in moist soil.
For Ex:Grapes,sugarcane,bananas,cactus,bougainvillea.

Layering:A branch of plant is pulled towards the ground and a part of it is covered with moist soil leaving the tip of branch exposed above the ground.After some time new root develops from the part of branch buried in the soil.The branch is then cut off from parent plant.
For Ex:Jasmine,lemon,guava,Strawberry.

Grafting:In this the cut stem of two different plants(One with root and other without root)are joined together in such a way that the two stems join and grow as a single plant.
For Ex:Apple,apricot,peach,pear

Wanda Petronski was a Polish immigrant. She was a socially outcast student who was often teased by the other students of the school and used to live in an impoverished area - Boggins Heights. Wanda used to wear the same faded, yet clean, blue dress to school each day. She sat in the last seat in the last row of her classroom, amidst the troublemakers, and was generally ignored by her teacher and by her fellow students. She was a very serene girl who laughed very rarely. She was very talented, skilled and patient.