Sr No |
Question |
Answer |
Remarks |
2 |
“—–” is an example of the conversion of potential to kinetic energy. |
slide |
In slide you raises your level from earth by climbing on the slide and gain potential energy. When you slide, you potential energy is converted to kinetic energy. |
3 |
“—–” is an example of the conversion of strain to kinetic energy. |
catapult |
Catapult is having a string which when pulled and released, the object gains kinatic energy |
4 |
Water supply to our house on 5th floor is due to conversion of |
potential energy in the overhead tank to kinetic energy |
The water from the ground level is raised to overhead tank using electric energy. The water in the overhead tank possess potential energy which makes the water to move in pipe and comes out in the bathroom with speed. |
5 |
The atoms of a material is always moving in random motion. What energy makes it moving? |
internal |
internal |
6 |
“—–” converts electric energy to mechanical energy. |
Fan |
The electric energy is converted to rotation of the motor on which the fan blades are attached which sucks the air and moves forward. |
7 |
Voltage of electric supply is synonym with |
potential energy in the overhead tank to kinetic energy |
The voltage is available at the socket of a power supply. As soon as the plug is inserted and switch is on, the current starts moving into the appliance to do work. |
8 |
“………” converts kinetic energy to strain energy |
baloon |
when air is blown in the baloon, the Kintic energy of the air is converted in stretching the baloon rubber |
9 |
What energy transformation takes place in plants? |
light to chemical energy |
The light energy is converted to chemical enegy by the process of photo synthesis |
10 |
What is the unit of energy stored in food? |
Kilo-Jules |
The energy stored in food is measured in kilo-Jules (kJ) or also called kilo-calorie . You should also know that 1 kJ-4.2kcal. |
11 |
What is dissipating energy? |
The energy wasted in conversion of energy from one form to another |
Conversion of energy to another form is never full and some energy is always wasted. The energy wasted is called dissipating energy is difficult to use. Mostly the energy is wasted in heat energy to the environment. |
12 |
Sound does not travel in |
vacuum |
Sound does not travel in vacuum. |
13 |
The speed of light in liquid is more than |
gas |
sound energy travels faster in liquid since the atoms are closed as compared to gas. It is fastest in metal. |
14 |
What is unit of sound measurement? |
dB |
Sound energy is measured in decibel and represented as dB. |
15 |
What is echo? |
reflection of sound |
When air is reflected or return from a distance of more than 35 meter away, you hear the your own sound again. |
16 |
What is referberation? |
hearing you sound feeble |
When the room is empty with no furniture or soft cushion, the air is not absorbed and reflect and the reflected sound superimpose on your sound and one hears louder |
17 |
What is ultrasound? |
ultrasound is high frequency sound which human being cannot hear |
Ultrasound is high frequency sound which cannot be heard by normal human ear. It is used in medical sound when high frequncy sound is passed to human body and refelcted sound is analysed to know the body structure. |
18 |
What is acoustic panels? |
accounstic panels are used to absorb sound |
Accoustic panels are used in sound studio where the recording engineer wants the sound is absorbed by the panels and should not be reflected back to create noise in the original sound. |
19 |
How string phone works? |
all of them |
|
20 |
Which of the following animals can hear ultrasounds? a) Dogs, b) Whales, c) Bats, d) Dolphins |
a, b and c |
Animals like dogs, whales, bats, dolphins, etc. can hear sounds of frequencies more than 20,000 Hz, i.e., ultrasounds. These sounds are inaudible to humans. However, they are important for these animals as it helps them to locate prey and escape from obstacles. |