Refer the given figure, what is the total length of "Double folded Ribbon"?
Which of the following statements regarding pinhole camera is/are not correct?
(i) Pinhole camera forms virtual image
(ii) Principle of image formation in pinhole camera is rectilinear propagation of light.
(iii) Pinhole in a pinhole camera acts as the lens.
B(i) and (ii)
C(ii) and (iii)
D(i), (ii), and (iii)
Observe the given experimental set-up carefully.
Which of the following could be the possible observation and inference drawn?
A The solution becomes blue-green due to formation of copper oxide, P is acidic.
B The solution becomes blue-green due to formation of copper chloride, P is basic.
C The solution becomes white due to formation of calcium hydroxide, P is basic.
D The solution becomes white due to formation of calcium oxide, P is acidic.
the correct answer should be (b) because copper cant displace h2 from HCl
Four students P, Q, R and S noted the initial colour of the solutions kept in beakers I, II, III and IV. After inserting zinc rods in each solution and leaving them undisturbed for two hours, the colour of each solution was again noted in the form of table given below :
Which student noted the colour change in all the four beakers correctly?
the correct answer is not given because acc. to reactivity series only beaker 1 will have some change