A student added acetic acid to test tubes I, II, III and IV containing the labelled substances and then brought a burning splinter near the mouth of each test tube.
Acetic acid reacts with solid sodium hydrogen carbonate
Slowly forming no gas
Vigorously with effervescence
Slowly without effervescence
Slowly without effervescence
To find the focal length of a concave mirror, Sita should choose which one of the following set-ups?
A mirror holder and a screen holder
A screen holder and a scale
A mirror holder, a screen holder and a scale
A mirror holder, a screen holder and a scale
In these diagrams, the angle of refraction r has been correctly marked in which diagram?
I
II
III
III
To determine the focal length of a convex lens by obtaining a sharp image of a distant object, the following steps were suggested which are not in proper sequence:
I. Hold the lens between the object and the screen.
II. Adjust the position of the lens to form a sharp image.
III. Select a suitable distant object.
IV. Measure the distance between the lens and the screen.
The correct sequence of steps to determine the focal length of the lens is,
III, I, II IV
III, I, IV, II
III, IV, II, I
III, IV, II, I
Iron nails were dipped in an aqueous solution of copper sulphate. after about 30 mintues, it was observed that the colour of the solution changed from
Colourless to light green
Blue to light green
Blue to colurless
Blue to colurless
By using a convex lens, a student obtained a sharp image of his class-room window grill on a screen. In which direction should he move the lens to focus a distant tree instead of the grill?
Towards the screen
Away from the screen
Very far away from the screen
Very far away from the screen
For a ray of light passing through a glass slab, the lateral displacement was correctly measures as,
AB
PQ
CD
CD
Vapour of acetic acid smell
Pungent like vinegar
Sweet like rose
Suffocating like sulphur dioxide
Suffocating like sulphur dioxide
A cleaned aluminium foil was placed in an aqueous solution of Zinc sulphate. when the aluminium foil was taken out of zinc sulphate solution after 15 minutes, its surface was found to be coated with a silvery grey deposit. From the above observation, it can be concluded than zinc
Aluminium is more reactive than zinc.
Zinc is more reactive than aluminium
Zinc and aluminium both are equally reactive
Zinc and aluminium both are equally reactive
