SEQUENCE (BOUNDED & UNBOUNDED) BSC 2ND SEM

WORK AND ENERGY (FOR CLASS 8)

WORK: The action for producing the displacement by exerting force on object is called work.

• Work done on object depends on

a) displacement
b) force exerted on object

• work= force x displacement in direction of force.
• SI unit of work is Joule.

ENERGY: Capacity of doing work in objects is called energy.

• SI unit of energy is Joule, as work and energy are equivalent to each other.
• There are various types of energy. eg. Mechanical energy, Heat energy, Chemical energy, Light Energy, Chemical energy, Magnetic energy, Sound energy, Atomic energy.

Mechanical Energy: Mechanical Energy is combination of Kinetic Energy and Potential Energy.

1. Kinetic Energy:(KE): The capacity of doing work due to an object is in motion is called Kinetic Energy.
2. Potential Energy:(PE): When we make change in position or shape of an object, then mechanical energy stored in it is called potential energy.

Heat Energy: Energy stored in burning objects of hot objects is called Heat Energy.
Chemical Energy: Energy stored in fuels is called Chemical Energy.
Light Energy: Energy stored into light of sun or bulb, etc is called Light Energy

Electric Energy: Energy obtained due to change in motion is called Electric Energy.
Magnetic Energy: Energy stored in magnetic field is called Magnetic Energy.
Sound energy: Energy stored in sound (vibration) is called Sound Energy.
Atomic Energy: Energy obtained from nuclear fusion or fission is called Atomic Energy.

THE REAL NUMBER SYSTEM (BSC 2ND SEM)

• Field Properties: A field is an algebraic structure (F,+,.) consisting of a non-empty set F and two binary operations '+' and '.' (called addition and multiplication respectively) defined on it and satisfying the following axioms for any element a,b,c of the set F

     (A) a+b=b+a and ab=ba (commutative laws)
     (B) (a+b)+c=a+(b+c) and (ab)c=a(bc) (associative laws)
     (C) a(b+c)=ab+ac (distributive law)
     (D) There are distinct real numbers 0 and 1 such that a+0=a and a.1=a for each a
     (E) For each 'a' there is a real number '-a' such that a+(-a)=0 and if a≠0 there is a real number 1/a  such that a(1/a)=1
     A set on which two operations are defined so as to have properties (A) to (E) is called field.
 

• Ordered Field: The real number system is ordered by the relation <, which has the following properties--

     (F) For each pair of real numbers a and b, exactly one of the following is true
          a=b or a<b or b<a
     (G) If a<b and b<c then a<c (the relation < is transitive)
     (H) If a<b then a+c<b+c for any c and if 0<c, then ac<bc.
     A field with an order relation satisfy (F) to (H) is an ordered field. 

COMMUNICATION (part-1)(BSC 1ST SEM)

1. What is communication?
ans:  Communication means exchange of thought, emotion and ideas. This is done through gesture, expression, signs, symbols and voice from one person to another.

2. What are the types of Communication?
ans: There are various types of communication which can be categorized as follows-
 i) Medium: Verbal and Non-verbal Communication.
 ii) Channel:  Formal and Informal Communication.
 iii) Level: Inter-personal, Intra-personal and Group Communication

3. What are the various elements of communication? 
ans: 
 i) Sender: Sender starts the communication process. They send the information.
 ii) Encoding: The process through which the massage is sent is called Encoding.
 iii) Massage: Massage is the information.  In other words it is the subject matter.
 iv) Medium: The information needs to be sent through a particular medium which is determined by encoding.
 v) Decoding: It is the process through which the receiver makes sense of what has been commuted.
 vi) Receiver: The person who receives the information is called the receiver.
 vii) The return-back massage from the receiver to the sender is called the Feedback.