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This question is about waves in the electromagnetic (e.m.) spectrum - Edexcel - GCSE Physics - Question 9 - 2022 - Paper 1
Question 9
This question is about waves in the electromagnetic (e.m.) spectrum. (a) The potential danger associated with the waves of the e.m. spectrum increases as A freq... show full transcript
Worked Solution & Example Answer:This question is about waves in the electromagnetic (e.m.) spectrum - Edexcel - GCSE Physics - Question 9 - 2022 - Paper 1
Step 1
Step 2
b) (i) Calculate the wavelength of the microwaves.
Answer
To calculate the wavelength (
theta ) of the microwaves, we can use the formula:
wavelength = \frac{velocity \ of \ light}{frequency}\n$$ Substituting the values:wavelength = \frac{3.00 \times 10^8 \ m/s}{2.45 \times 10^9 \ Hz} \approx 0.122 \ m\n$$
Therefore, the wavelength is approximately 0.122 m.
Step 3
b) (ii) Calculate the total amount of energy that must be supplied to the oven.
Answer
The microwave oven is 55% efficient, meaning that the efficiency can be represented as a decimal (0.55). If the oven transfers 42,000 J of energy to the food, the total energy supplied (E) can be calculated using the formula:
E = \frac{Energy \ transferred}{Efficiency}\n$$ Substituting the values:E = \frac{42000 \ J}{0.55} \approx 76363.64 \ J\n$$
Therefore, the total energy supplied to the oven is approximately 76,364 J.
Step 4
c) Compare X-rays with radio waves.
Answer
X-rays and radio waves serve different purposes in technology and healthcare. X-rays are primarily used in medical imaging to view the inside of the body, while radio waves are used for communication technologies such as radio broadcasting and mobile communications.
In terms of production, X-rays are generated when high-energy electrons striking a metal target lose energy, while radio waves are produced by oscillating electrons in antennas.
Thus, while both types of radiation involve electrons, they are generated through different mechanisms and are utilized in vastly different applications for society.