A) The most essential characteristic of a computer is its automatic operation. Once programmed, it can perform a sequence of operations without human intervention.

Here are the answers to the long answer questions:

a) The most essential characteristic of a computer is its automatic operation. Once programmed, it can perform a sequence of operations without human intervention.

b)

• Speed: A computer can process vast amounts of data and perform complex calculations in a fraction of a second, far exceeding human capabilities. This is measured in operations per second.
• Accuracy: Computers are designed to perform tasks with extremely high precision and consistency. They produce error-free results, provided the input data and instructions are correct.

c)

• Capabilities:
  1. Speed: Processes data very quickly.
  2. Accuracy: Provides error-free results.
  3. Storage: Can store large amounts of data.
  4. Versatility: Can perform a wide range of tasks.
• Limitations:
  1. Lack of IQ: Cannot think or make decisions on its own.
  2. No Feelings: Does not possess emotions or intuition.
  3. Dependence on Humans: Requires human input and programming.
  4. No Common Sense: Cannot understand context or apply common sense.

d)

• Advantages:
  1. High Speed: Completes tasks rapidly.
  2. Accuracy: Ensures reliable and precise results.
  3. Large Storage Capacity: Stores extensive data efficiently.
  4. Automation: Performs repetitive tasks without human intervention.
• Disadvantages:
  1. Cost: Initial purchase and maintenance can be expensive.
  2. Security Risks: Vulnerable to viruses, hacking, and data breaches.
  3. Health Issues: Prolonged use can lead to eye strain, RSI, and other health problems.
  4. Job Displacement: Automation can reduce the need for human labor in certain sectors.

e) A computer is known as an automatic machine because, once given a set of instructions (a program), it can execute those instructions sequentially and perform tasks without continuous human guidance or intervention. It follows the programmed logic to process data and produce output independently.