Who invented the microwave oven, a kitchen appliance that cooks food using microwave radiation?

Introduction / Context:
The microwave oven is now a standard appliance in kitchens around the world, allowing quick heating and cooking of food. Its invention is tied to radar research and an accidental discovery about how microwaves can heat objects. This question checks if you know the name of the engineer who turned that discovery into a practical cooking device, an important example of how military technology can lead to domestic applications.

Given Data / Assumptions:

• The device is the microwave oven, not general microwave technology.
• The inventor noticed food being heated by radar or microwave energy.
• The options list inventors associated with pens, jeans and time zones as distractors.
• Only one name is historically connected to the microwave oven invention.

Concept / Approach:
Percy LeBaron Spencer, an American engineer working with radar equipment, observed that a chocolate bar in his pocket melted when exposed to microwaves from a magnetron. This led him to experiment with popcorn and eggs, and eventually to invent the first microwave cooking device. He filed patents and helped commercialise microwave ovens. Waterman is associated with fountain pens, Levi Strauss with denim jeans and Sandford Fleming with standard time zones and railway time. None of these relates to microwave cooking, so Percy LeBaron Spencer is the correct answer.

Step-by-Step Solution:
Step 1: Focus on the clue that the device is a kitchen appliance using microwave radiation.Step 2: Recall that Percy LeBaron Spencer discovered microwave heating effects during radar work and then invented the microwave oven.Step 3: Locate his name, Percy LeBaron Spencer, as option C in the list.Step 4: Recognise that Waterman developed fountain pens, Levi Strauss made jeans and Fleming worked on timekeeping, not cooking devices.Step 5: Select Percy LeBaron Spencer as the correct answer.

Verification / Alternative check:
Histories of household appliances and microwave technology consistently credit Percy Spencer with inventing the first practical microwave oven. Many accounts retell the story of the melting chocolate bar and subsequent experiments. No reliable source names Waterman, Strauss or Fleming as microwave oven inventors. This strong agreement across references confirms that Spencer is the correct choice in general knowledge questions.

Why Other Options Are Wrong:
Lewis Edson Waterman is known for improvements to the fountain pen, which helped create reliable writing instruments. Levi Strauss was a businessman whose company produced durable denim trousers for miners and workers. Sir Sandford Fleming is remembered for proposing worldwide standard time zones and influencing railway timetables. None of these achievements involve microwave cooking, so the corresponding options cannot be correct for this question.

Common Pitfalls:
Some students may confuse microwave oven invention with broader electromagnetic research, incorrectly thinking of Maxwell or Hertz, who do not appear in this list. Others may choose a familiar name without linking it to the correct domain. To avoid such mistakes, associate Percy Spencer with radar, melted chocolate and microwave ovens, and remember that this combination is unique among common inventors.

Final Answer:
The microwave oven was invented by Percy LeBaron Spencer.