The surface of a lake is frozen in severe winter, but the water at its bottom is still liquid. What is the reason ?
The clouds float in the atmosphere because of their low:
Consider the following statements: If there were no phenomenon of capillarity
I. it would be difficult to use a kerosene lamp
II. one would not be able to use a straw to comsume a soft drink
III. the blotting paper would fail to function
IV. the big trees that we see around would not have grown on the earth
Which of the statements given above are correct ?
Consider the following phenomena:
I. Size of the sun at dusk.
II. Colour of the sun at dusk.
III. Moon being visible at dawn.
IV. Twinkle of stars in the sky.
V. Polestar being visible in the sky.
Which of the above are optical illusions ?
Two wires have their lengths, diameters and resistivity all in the ratio of 1: 2. If the resistance of the thinner wire is 10 ohm, the resistance of the thicker wire is:
When a mirror is rotated by an angle θ, the reflected ray will rotate by:
Consider the following statements: A 4-wheel vehicle moving in a sharp circular path at high speed will:
I. overturn about its outer wheels
II. overturn about its inner wheels
III. skid outwards
IV. skid inwards
Which of these statements are correct ?
Consider the following statements:
I. If a person looks at a coin which is in a bucket of water, the coin will appear to be closer than it really is.
II. If a person under water looks at a coin above the water surface, the coin will appear to be at a higher level than it really is.
Which of the above statements is/are correct ?
When light waves pass from air to glass, the variables affected are:
One astronomical unit is the average distance between: