Question
What is the wavelength of visible spectrum?
Solution
The visible spectrum is the portion of the electromagnetic spectrum that is visible to (can be detected by) the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light. A typical human eye will respond to wavelengths from about 390 to 750 nm in terms of angstrom it is in between 3900 - 7600 A°.
In a certain school, 60% of the students are girls, and the rest are boys. If the number of boys in the school is 480, how many students are there in to...
Two numbers are less than a third number by 25% and 31% respectively. Find the percent by which the second number is less than the first.
When A's income is doubled and his expenditure remains unchanged, his savings increase by Rs. 40,000. If B's income is 15% higher than A's initial incom...
Rani appeared for an examination which had four papers, with the weightage of the four papers being in the ratio 1:2:3:x She secured 60 percent marks i...
Out of her total income, Priya spent 20% on rent, 50% of the remaining income on groceries, and saved 40% of the income left after her expenses.
A money lender finds that due to a fall in the annual rate of interest from 10% to 8(3/4)%, his year's income diminishes by ₹84.50. Find his capital.
- Sneha spent 18% of her income on donations and out of the remaining amount, she spent 22% on household expenses, 28% on shopping, 12% on transportation, an...
- If the price of a milk packet is reduced by 20%, by what percentage should a family increase its consumption of milk to ensure that their total expenditure...
The price of a laptop undergoes two consecutive changes over two months. In the first month, its price decreases by 10%, followed by an increase of 20% ...
- A school purchased a total of 15000 books where 20% of the books were textbooks and the remaining were reference books. If 75% of the textbooks purchased a...
Relevant for Exams:
