Competency based education is essential for

Answer:

Question 1:

Light is

(a) visible and also makes objects on which it falls visible.

(b) invisible but makes objects on which it falls visible.

(c) invisible but becomes visible when it falls on an object.

(d) sometimes visible and sometimes invisible but it always makes objects on which it falls visible.

ANSWER:

(b) invisible but makes objects on which it falls visible.

Light is invisible by itself but makes visible the objects on which it falls.

Page No 140:

Question 2:

The shape and size of a shadow depends on

(a) the shape and size of the object.

(b) the position of the source of light.

(c) the distance between the source of light and object.

(d) all of the above

ANSWER:

(d) all of the above.

The shape and the size of a shadow depends upon the shape and size of the object, the position of the source of light and the distance between the source of light and the object.

Page No 140:

Question 3:

Which of these is not a source of light?

(a) sun

(b) moon

(c) lighted candle

(d) stars

ANSWER:

(b) moon

The moon is not a source of light. It shines by reflected light.

Explanation:

The image of a candle flame in a pinhole camera is inverted (option b).

• Light travels in a straight line.
• The rectilinear motion of light is a phenomenon of light.

• This phenomenon has been applied to a pinhole camera.

• The image formed due to this is always real, diminished, and inverted in size.
• A great example of a pinhole in nature is that of the image of the sun as patches when we pass from under a tree.
• These real, diminished, inverted image of the sun happens due to the passing of light from the gap of tree leaves.
• Thus when candlelight passes through the pinhole camera it gets inverted.
• Hence option B is correct and more accurate.

#SPJ2

Answer:

The total potential energy of an elastic body , is defined as the sum of total strain energy (U) and the work potential (WP) .

Answer:

POTENTIAL ENERGY, ∏. The total potential energy of an elastic body , is defined as the sum of total strain energy (U) and the work potential (WP) .

Explanation:

The True Part Expression of a Java conditional operator or Ternary operator ____ return a value. Explanation: The True/False part expression should evaluate to a constant literal.

Answer:

water doesnt get wet

Explanation:

its already clean in the ocean