Question 1 :
Does the speed of sound increase or decrease on a hotter day?
Question 2 :
Mention whether the statement is true or false.
Cross between two varieties is called as inter specific hybridisation.
Question 3 :
Among the given options, which one is not correct for the use of large amount of fertilisers and pesticides?
Question 4 :
Seema visited a Natural Gas Compressing Unit and found that the gas can be liquefied under specific conditions of temperature and pressure. While sharing her experience with friends she got confused. Help her to identity the correct set of conditions.
Question 6 :
Four men lift a 250 kg box to a height of 1 m and hold it without raising or lowering it. Why do they get tired while holding it?
Question 7 :
Four men lift a 250 kg box to a height of 1 m and hold it without raising or lowering it. How much work do they do in just holding it?
Question 8 :
Mention whether pumping of the heart is on the basis of voluntary or involuntary muscles.
Question 12 :
Compute the ratio by mass of the combining elements in Ammonia.
Question 13 :
Mention whether the statement is true or false.
Hybridisation means crossing between genetically dissimilar plants.
Question 14 :
Mention whether the statement is true or false.
Cross between plants of two species is called as inter varietal hybridisation.
Question 16 :
A motorcyclist drives from point A to point B with a uniform speed of $30 kmh^{–1}$ and returns back to point A with a uniform speed of $20 kmh^{–1}$. Find the average speed of the motorcyclist.
Question 17 :
In a sample of ethyl ethanoate $(CH_3COOC_2H_5)$ the two oxygen atoms have the same number of electrons but different number of neutrons. Which of the following is the correct reason for it?
Question 18 :
What should be the minimum distance between the listener and the reflector to hear an echo of sound propagating with a speed v $m s^{–1}$?
Question 19 :
Compute the ratio by mass of the combining elements in Carbon Monoxide.
Question 20 :
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In the above figure, velocity versus time graph of a ball of mass 50 g rolling on a concrete floor is shown. Calculate the acceleration of the ball.
Question 27 :
Is bending of an iron rod a physical change or not?
Question 28 :
Mention whether the statement is true or false.
Manure increases the water holding capacity of sandy soil.
Question 29 :
If speed of sound in air is $340 m s^{–1}$, calculate its frequency when wavelength is 0.85 m.
Question 32 :
Why does the speed of sound increase on a hotter day?
Question 33 :
Mention whether writing with hand is on the basis of voluntary or involuntary muscles.
Question 34 :
Mention whether movement of chocolate in your intestine is on the basis of voluntary or involuntary muscles.
Question 36 :
Compute the ratio by mass of the combining elements in Aluminum Fluoride.
Question 39 :
Who discovered the bacterium peptic ulcer pathogen for the first time?
Question 40 :
Mention whether the statement is true or false.
Manure helps in draining out of excess of water from clayey soil.