In the history of computers, second generation computers are generally considered to have been developed during which time period?

Introduction / Context:
Computer history is often divided into generations based on major technological shifts. The first generation used vacuum tubes, the second generation used transistors, the third generation introduced integrated circuits, and the fourth generation brought microprocessors. Each generation is associated with an approximate time period. Knowing these rough dates helps you answer history of computing questions frequently asked in general knowledge exams. This question focuses on the time span for second generation computers.

Given Data / Assumptions:

• The term second generation refers to transistor based computers.
• Options provide different time ranges: 1956 to 1963, 1970 to 1975, 1975 to 1980, and 1990 to 2000.
• We assume the standard school textbook classification of generations.
• The time ranges are approximate, but the first option matches the commonly cited period.

Concept / Approach:
Second generation computers replaced bulky and unreliable vacuum tubes with transistors, which were smaller, faster, and more energy efficient. This transition occurred in the late 1950s and early 1960s. Most education materials place second generation computers roughly between 1956 and 1963. Third generation computers using integrated circuits emerged around the mid 1960s, and fourth generation microprocessors became prominent in the 1970s. The later date ranges in the options correspond more closely to third and fourth generation developments, not to the transistor era. Therefore, the correct answer is the period 1956 to 1963.

Step-by-Step Solution:
Step 1: Identify the technology of second generation computers. They used transistors instead of vacuum tubes. Step 2: Recall the typical dates given in textbooks. Second generation is usually described as covering the late 1950s to early 1960s. Step 3: Match these dates to the options. Option A, 1956 to 1963, fits this textbook period. Step 4: Evaluate option B and C. The early and mid 1970s are more closely associated with fourth generation microprocessor based systems. Step 5: Evaluate option D. The 1990 to 2000 period belongs to very late fourth generation and beyond, not to second generation.

Verification / Alternative check:
Historical overviews of computing commonly summarise generations as follows: first generation (roughly 1940 to 1956), second generation (about 1956 to 1963), third generation (1964 to 1971), and fourth generation (from 1971 onwards). While exact years vary slightly between sources, they consistently place second generation in the late 1950s and early 1960s. The later ranges in the other options fall well outside this period. Therefore, option A aligns best with the standard generation timeline taught in exams.

Why Other Options Are Wrong:
Option B (1970 to 1975): These years are more representative of early microprocessor based fourth generation systems, not second generation transistors. Option C (1975 to 1980): This period is still within the microprocessor era, far beyond second generation. Option D (1990 to 2000): This range covers very advanced PCs and networking technology, long after the second generation era ended.

Common Pitfalls:
Students sometimes confuse the generations because later periods are more familiar or because they focus on brand names like personal computers rather than on underlying hardware technology. Exam setters may include tempting dates such as 1970 to 1975, which are closer to when many people first encountered computers, but those dates refer to later generations. To avoid mistakes, remember that second generation equals transistor based machines and associate them with the mid twentieth century, specifically around 1956 to 1963.

Final Answer:
Second generation computers were developed during the period 1956 to 1963 in the commonly used generation classification.