Question Discussion & Solution

Concept:

Latent heat: It is the amount of heat needed to change the state of a unit mass of any substance without changing its temperature.

i.e., we can say that heat needed to supply for changing its state will be directly proportional to the mass m of the substance.

∴Q ∝ m

i.e.,Q = mL

The SI unit of Latent heat is J/Kg and the CGS unit is Cal/g respectively.

Where,

m = mass of an object

L = Latent heat

Q = amount of heat needed to change the state of matter of mass m 

Explanation:

From the above explanation, we can see that Amount of heat needed to melt a unit mass of a substance is directly proportional to the amount of mass of an object since the Latent heat of a material is constant.

i.e., Q ∝ m ⇒ Q = mL

Thus the unit of latent heat can be expressed as \(L=\frac{Q}{m}\Rightarrow L=\frac{Joules}{kg}\)

Concept

The javac command in Java compiles a program from a command prompt.

It reads a Java source program from a text file and creates a compiled Java class file.

Syntax

javac filename [options]

For example, to compile a program named Abc.java, use this command:

javac Abc.java

In this figure (i) shows that it moves 90 degree clockwise then get figure (ii). Similarly, In figure (iii) moves 90 degree clockwise then get next figure which is shown bellow -

Hence, option 2 is the correct answer.

Polymorphism:-

• The word polymorphism means having many forms. In simple words, we can define polymorphism as the ability of a message to be displayed in more than one form.
• A real-life example of polymorphism is when two people have distinct characteristics at the same time. At the same time, he is a father, a spouse, and an employee. As a result, the same person behaves differently in different settings. 
•  Polymorphism is considered one of the important features of Object-Oriented Programming.

Polymorphism is mainly divided into two types:

• Compile-time Polymorphism
• Runtime Polymorphism

Compile-time polymorphism

This is achieved by function overloading or operator overloading.

• Function Overloading - When there are multiple functions with the same name but different parameters then these functions are said to be overloaded
• Operator overloading - When there are multiple operations that can be performed by using a single operator is called operator overloading for example operator ‘+’ when placed between integer operands, adds them, and when placed between string operands, concatenates them.

Run Time Polymorphism

It is achieved by Function Overriding

Additional Information

Encapsulation

• It is the process or method to contain the information.
• Wrapping of data and function into a single unit is called data encapsulation
• Encapsulation is a method to hide the data in a single entity or unit along with a method to protect information from outside.
• It can be implemented using by access modifier.  

Inheritance

The capability of a class to derive properties from another class is called Inheritance

• The class that inherits properties from another class is called Subclass or Derived Class.
• The class whose properties are inherited by a subclass is called Base Class or Superclass.

Syntax for Inheritance

class derived_name : access_mode base_class

{

//body of the derived class

};

A drone is a male honey bee. Similarly, A male deer is called stag.