Question Discussion & Solution

Input Devices:

• Input devices are the component of the computer system that accepts incoming data and instructions.
• It converts them into a pattern of electrical signals in binary code that is understandable to a digital computer.

Output Devices:

• Output devices are the component of a computer system that converts the digitized signals into a form understandable to the user.
• The output devices are generally known as the reverse of input devices.
• Output devices also send data from one computer system to another.

Key Points

•  A Visual Display Unit (VDU) is also referred to as a Monitor and VDU (video display unit), a monitor is an output device that displays video images and text.
• A printer is an external hardware output device that takes the electronic data stored on a computer or other device and generates a hard copy.
• A floppy disk is a type of disk storage composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic enclosure lined with fabric that removes dust particles. It can be both an input and output device.​

Important Points

The Central Processing Unit (CPU):

• The CPU is the brain of the computer.
• Sometimes referred to simply as the processor or central processor, the CPU is where most calculations take place.
• The CPU executes the programs and controls the operation of all the hardware.
• A central processing unit (CPU), also called a central processor, main processor, or just processor is the electronic circuitry that executes instructions comprising a computer program.
• The CPU performs basic arithmetic, logic, controlling, and input/output (I/O) operations specified by the instructions in the program.

​Thus, CPU is not a computer output device.

Mistake Points

• The question is "Which one is not a computer output device?"
• Floppy is both input and output.
• CPU is the only option that is not an output device.

Additional Information

The basic difference between Input and Output devices:

In this question shows that Cauliflower is vegetable but remaining Guava, Pomegranate and Mango are fruit. 

Hence, "Cauliflower" is the correct answer. 

The correct answer is chemical energy.

Key Points

• The dry cell is a type of electric battery which is used for portable electrical devices.
• Electricity is produced through the dry cells from electrochemical energy. Hence, Option 1 is correct.
• A common dry cell is a zinc-carbon cell.
• The electrolyte is immobilized as a paste by a dry cell, with just enough humidity in it to allow current to flow.
• Like a wet cell, a dry cell can work without spilling in any direction, because there is no free liquid in it.
• The versatility makes it ideal for mobile devices.
• The first wet-cell batteries, in comparison, were usually fragile glass containers featuring lead rods sticking from an open-top.
• Hence, they required careful handling to prevent spillage.
• The dry-cell battery development made a significant advance in battery safety and portability.
• Batteries render electricity from chemical energy.
• Batteries consist of one or more different parts, or cells, which contain an electrolyte called a chemical.
• Every cell has two electrodes that are electrically conductive immersed in its electrolyte.
• The electrodes consist of different materials; one releases electrons into the electrolyte, and the other absorbs them.
• Once an electrical system is attached to the electrodes, an electrical current passes through it and supports its operation with electric power.
• The energy contained in the dry cell is therefore in the form of chemical energy.

Additional Information

• Thermal energy
  • It is also called heat energy 
  • It is produced when a rise in temperature causes atoms and molecules to move faster and collide with each other.
  • The energy that comes from the temperature of the heated substance is called thermal energy.
  • Thermal energy is energy that comes from a substance whose molecules and atoms are vibrating faster due to a temperature rise.
• In physical sciences, mechanical energy
  • It is the sum of potential energy and kinetic energy.
  • It is the macroscopic energy associated with a system.
  • The principle of conservation of mechanical energy states that if an isolated system is subject only to conservative forces, then the mechanical energy is constant.
• Nuclear power
  • It is the use of nuclear reactions to produce electricity.
  • Nuclear power can be obtained from nuclear fission, nuclear decay, and nuclear fusion reactions.
  • Presently, the vast majority of electricity from nuclear power is produced by nuclear fission of uranium and plutonium in nuclear power plants.

The correct answer is Chloroplast.

Key Points

• Photosynthesis:
  • Photosynthesis definition states that the process exclusively takes place in the chloroplasts through photosynthetic pigments such as chlorophyll a, chlorophyll b, carotene, and xanthophyll.
  • All green plants and a few other autotrophic organisms utilize photosynthesis is to synthesize nutrients by using carbon dioxide, water, and sunlight.
  • The by-product of the photosynthesis process is oxygen.
  • Photosynthesis occurs when plants use light energy to convert carbon dioxide and water into glucose and oxygen.
  • Leaves contain microscopic cellular organelles known as chloroplasts.
  • Each chloroplast contains a green-colored pigment called chlorophyll.
  • Light energy is absorbed by chlorophyll molecules whereas carbon dioxide and oxygen enter through the tiny pores of stomata located in the epidermis of leaves.
  • Another by-product of photosynthesis is sugars such as glucose and fructose.
  • These sugars are used by the plants as an energy source, which helps them to grow.
  • Photosynthesis also applies to other organisms besides green plants.
  • These include several prokaryotes such as cyanobacteria, purple bacteria, and green sulfur bacteria.
  • These organisms exhibit photosynthesis just like green plants.
  • The glucose produced during photosynthesis is then used to fuel various cellular activities.
  • The by-product of this physio-chemical process is oxygen.

Ocean is the mass of water.

Similarly,

Desert is the mass of sand.