The correct answer is (d) All of the above. To solve the food problem, increased production and proper storage of food grains are essential. Additionally, people must have purchasing power and easy access to food to ensure food security for ...
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The correct answer is (b) 1.4 m. The wavelength (λ) is calculated using the formula: λ = v/f where v = 350 m/s (velocity of sound) and f = 250 Hz (frequency). λ = 350/250 = 1.4m. Class 9th Science ...
The correct answer is (c) Frequency. When a sound wave moves from air to water, its speed and wavelength change due to the difference in medium density. However, frequency remains unchanged because it depends only on the source of the ...
The correct answer is (c) 200 Hz. The frequency (f) is given by the formula: F = 1/T where T = 0.005 s. F = 1/0.005 = 200 Hz. Class 9th Science NCERT MCQ Questions NCERT Books MCQ Questions Session ...
The correct answer is (b) 1815 m. The distance is calculated using distance = speed × time. Given the speed of sound as 330 m/s and time as 5.5 s, the distance is 330 × 5.5 = 1815 m. Class ...