Light and Sound - 8th Std Science
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Question 1 |
Reflection from a smooth surface is called ________ reflection.
Regular | |
Irregular | |
Multiple | |
Total internal |
Question 2 |
The angle between the incident ray and the normal is called ________
Angle of incidence | |
Angle of reflection |
Question 3 |
The bouncing of light from a surface of a body is known as
Refraction | |
Total internal reflection |
Question 4 |
The path of light is known as ray it is represented by
a straight line | |
Triangle mark |
Question 5 |
When the light rays meet at a point it is
Divergent beam | |
Convergent beam |
Question 6 |
If the light rays move away from a point it is called
Divergent beam | |
Convergent beam |
Question 7 |
The angle in between reflected ray and the normal drawn from the point of incidence is called
Angle of incidence | |
Angle of reflection |
Question 8 |
The principle applied in periscope is
Refraction | |
Multiple reflection |
Question 9 |
A swimming pool appears more shallow than its actual depth because of
Reflection | |
Refraction |
Question 10 |
When light ray passes from Air to glass it gets.
Deviated towards normal | |
Deviated away from normal |
Question 11 |
When light ray passes from glass to Air it gets.
Deviated towards normal | |
Deviated away from normal |
Question 12 |
The most comfortable distance the normal eye can read is about
25 cm | |
25 mm |
Question 13 |
Sound cannot travel through
Air | |
Vacuum |
Question 14 |
The lower end of the tuning Fork is called
Scapula | |
Stem |
Question 15 |
The upper end of the tuning Fork is called
Scapula | |
Prong |
Question 16 |
The unit of Frequency is
Hertz | |
Seconds |
Question 17 |
The unit of amplitude is
Hertz | |
Seconds |
Question 18 |
The unit of period is
Hertz | |
Seconds |
Question 19 |
Sounds of frequencies lesser than 20 Hz. and greater than 20,000 Hz. are called
Audible sounds | |
Inaudible sounds |
Question 20 |
Ultrasonic waves have a frequency of
20 Hz | |
Above 20,00 Hz |
Question 21 |
The animal which can hear sound waves above 20,000 Hz is
Rat | |
Dog |
Question 22 |
The working principle of a periscope is _________
Successive reflection from mirror | |
Successive reflection from two mirrors |
Question 23 |
A fruit appears to be bigger in a glass of water due to _______
refraction | |
Refection |
Question 24 |
Sound cannot travel in ________
Water | |
Air | |
Vacuum |
Question 25 |
When we touch the rinsing bell we can feel the _________
vibrations | |
Thunder | |
Lightening |
Question 26 |
An audible sound has the frequency range of ____
20Hz-20,000 Hz | |
10Hz-10,000Hz |
Question 27 |
The bouncing of light from a surface of a body is known as _________
Refraction | |
Reflection |
Question 28 |
We are able to see objects because of the phenomenon of _________ of light.
reflection | |
refraction |
Question 29 |
Light travels along a ________ line.
Cross | |
straight |
Question 30 |
Two or more rays of light form a_________
beam | |
Rays | |
Lazer |
Question 31 |
If the rays of light meet at a point, they form a_______ beam.
Concave | |
Convergent |
Question 32 |
The perpendicular line drawn to the surface at the point of incidence is called_______
normal | |
Abnormal |
Question 33 |
In a rough surface, light is __________ in all directions.
Isolated | |
scattered | |
Broken |
Question 34 |
The reflection in a rough surface is _______
irregular | |
Regular |
Question 35 |
We need _________ mirrors to see the back of our own head.
one | |
two | |
three |
Question 36 |
__________ established thatwhite light consists of seven colours.
Newton | |
einstein | |
tesla |
Question 37 |
_________ is the main cause of the brilliance of diamond.
Total internal reflection | |
Critical | |
Reflection |
Question 38 |
The most comfortable distance at which one can read with a normal eye is called _______
Least distance | |
most distance |
Question 39 |
The convex lens of an eye forms an image of the object on the screen called the _______
Iris | |
Retina | |
Cornea |
Question 40 |
Sound needs a _______ for propagation.
Fast | |
Medium | |
Slow |
Question 41 |
Sound cannot travel through ______
Air | |
Vacuum | |
Pressure |
Question 42 |
_________ helps us to communicate with one another.
Sound | |
Air | |
Heat |
Question 43 |
A to and fro motion of an object is called ______
vibration | |
Thunder | |
Lightening |
Question 44 |
The lower end of the tuning fork is called the_______
Leafplot | |
stem | |
Steam |
Question 45 |
Human audible range of frequencies is from ________ to ________ Hz.
20 to 20,000 | |
10 to 10,000 |
Question 46 |
Bats use _____ waves for their flight.
supersonic | |
ultrasonic | |
Ultrasound |
Question 47 |
Dogs have the ability to hear the sound of frequency higher than ______Hz
20,000 | |
10,000 |
Question 48 |
The ________ sound is called as noise.
unpleasant | |
Pleasant |
Question 49 |
An _________ is a device based on the principle of total internal reflection.
Copper wire | |
Optical fiber | |
Coaxial Wire |
Question 50 |
Match the following
- Irregular reflection a. Glass slab
- Multiple refection b. Optic fibre
- Refraction c. Periscope
- Total internal reflection d. Wood
2 4 3 1 | |
3 4 2 1 | |
4 1 2 3 | |
1 3 2 4 |
Question 51 |
Match the following
- Path of light a. regular reflection
- Rays meet at a point b. diverge
- Rays move away from a point c. irregular reflection
- Polished surface d. ray
- rough surface e. converge
4 3 5 1 2 | |
5 3 4 2 1 | |
4 2 1 3 5 | |
1 5 4 2 3 |
Question 52 |
Match the following
- Multiple reflection a. vibration
- Dispersion b. Hertz
- Human eye c. Newton
- Sound d. Kaleidoscope
- Frequency e. convex lens
5 3 2 1 4 | |
4 5 2 1 3 | |
2 1 3 5 4 | |
1 4 3 2 5 |
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There are 52 questions to complete.
