Difference between elastic body and Plastic body | Physics

                      Elastic body 

Definition: The property on account of which a body regain it's original size and shape on removal of external deforming force is called as elastic body.

Process:  It is reversible.

Ductility: It is less ductile in nature.

Modulus of elasticity: The ratio of stress to strain is low or equal.

Toughness: They have the ability to absorb energy up to fracture.

Bonds: The molecular bonds do not get fractured.

Shape and size: The shape and size does not change permanently.

Example: Rubber.

                               Plastic body

Plastic body: The property on account of which a body doesn't regain its original size and shape on removal of applied force is called as plastic body.

Process: it is irreversible

Ductility: They are highly ductile in nature.

Resilience: They have low yield strength.

Modulus of elasticity: The ratio of stress to strain is high.

Toughness: They do not have the ability to absorb energy up to a fracture.

Bonds: The molecular bonds are fractured.

Shape and size: The shape and size changes permanently.

Example: Plasticine

              

Explain Viva of Electrostatics | physics

1) What is electrostatics ?

Ans: It is the branch of science which deals with the study of electric charges and force between them.

2) Definition of electric charge 

Ans: It is the physical property of the matter that experience a force when it is place in electric field there are two types of electric charge. 

 i) Positive    charge (+ve)

 ii) Negative  charge  (-ve)

It is denoted by q and it's unit is coulomb (c)

3) Explain coulomb low of electrostatics or coulomb Inverse square low 

Statement: It states that the force of attraction or repulsion between two electric charges is directly proportional to the product of the two charges and inversely proportional to the square of the distance between them.

4) Definition of electric field.

Ans: The space around the electric charge is called as electric field.

5) Definition of electric flux density.

Ans: The total number of electric lines of force per unit Area is called as electric flux density. and it is denoted by (D).

6) Definition of Electric field intensity.

Ans: The force Acting Per unit charge is called as electric field intensity. It is denoted by (E).

7) Definition of Electric flux.

Ans: The total number of electric lines of force is called as electric flux. And it is denoted by ψ (Psi) it unit is coulomb.

8) Definition of electric potential.

Ans: The amount of work done in bringing a unit positive charge from the boundary of infinity to a given point against electric field is called as electric potential and it is denoted by (v).

9) Definition of absolute potential (v).

Ans: The amount of work done is bringing a unit positive charge at a given point is called as absolute potential.

10) Definition of electric potential between two points.

Ans: The amount of work done is bringing a unit positive from point R to points S is called as potential difference between two points.

List requirements of good servo motors.

 i) The linear relationship in between electrical control signal and the rotor speed over a wide range.

ii) The inertia of rotor should be as low as possible.

iii) A servo motor must stop running without any time delay, if control signal is removed.

iv) For low inertia, it is designed with large length to diameter ratio for rotors, compared to its frame size. The rotor of servomotor has very small diameter.

v) It's response should be as fast as possible, for quickly changing error signal, it must react with good response. This is attain by keeping torque to weight ratio high.

vi) It should be easily reversible. 

vii) It should have linear torque speed channel.

viii)  It's operation should be stable without any oscillation or overshoot.

State disadvantage of single mode optical fiber

 Ans:-

i) The laser required are costly and can be used with only one cable at a time.

ii) The dependency on laser it means that single mode cables are less versatile and more limited in their applications.

iii) Single mode solution are often more expensive to deploy and operate since laser based equipment generate more heat.

State advantage of WDM

 Ans:-

i) To use the full capacity of the fiber optic cable by allowing multiple beams of light at different frequencies on the same fiber    optic cable.

ii) Full duplex transmission is possible.

iii) Easier to reconfigure.

iv) Optical components are similar and more reliable.

v) This could be the best approach, as it is simple to implement.

vi) High security.

vii) Various optical channel can support different transmission formats.

3x^2-3 =5x solve this

 Ans:-

3x^2 - 3 = 5x 

Now we rearranging this expression ax2 + bx + c = 0 in that manner than we get,

3x^2 - 3 - 5x = 0

∴  3x^2 - 5x - 3 = 0

Now we solve this sum by quadratic formula,

1+1-12-12-67-972= What is the answer ?

 Ans:-

1+1-12-12-67-972 = ?

we solved this problem by golden formula of plus and minus

( +, - ). In this formula -1 -1 = -2, 

                                 ∴    -3 -3 = -6,

                                 ∴     1 + 1 = 2, 

                                 ∴     3 + 3 = 6

  ∴  1 + 1 - 12 - 12 - 67 - 972

         ↓                    ↓                   

         2                -1063    

                    

∴       2 - 1063 = 1061

This is our required Ans:- 1061

Find the product of place value and face value of 9 in the year of Independence.

 Ans:-

Year of Independence is 1947

so that, the face value of 9 in 1947 is = 9 

    ∴   the place value of 9 in 1947 is  = 900

Now the product of place value and face value of 9 in 1947 is = 9 × 900

                                                                                                     =  8100

The product of place value and face value of 9 in the year of Independence is = 8100

The ratio of the length of a rectangle to its width is 5:2. If the length of rectangle is 40 cm, what is its width​

 Ans:

Ratio of length and width of rectangle must be in proportion to the actual length and width of the rectangle.

Let we consider width of rectangle be = x

Given:-

Ratio of  Length : Width is = 5 : 2 respectively

Actual Length is = 40 cm

Now we know that, they are in proportion, so we can write them as,

5 : 2 = 40 : x

∴ 5/2 = 40/x

Cross multiplying, we get

5x = 80

x = 16 cm

Therefore width of rectangle is 16 cm.