A. 343 m/s
B. 230 m/s
C. 130 m/s
D. 430 m/s
Correct Answer: A. 343 m/s
The speed of sound in dry air at 20°C is approximately 343 meters per second (m/s). This value is affected by factors such as temperature, pressure, and humidity. In dry air at standard conditions, sound travels at this speed, which is commonly used as a reference value in physics and engineering calculations involving sound propagation
A. Noise
B. Sound
C. Echo
D. None of these
Correct Answer: C. Echo
The correct answer is C. Echo. When sound waves reflect off surfaces such as floors, ceilings, or walls and return to the listener’s ears after a brief delay, it creates an audible repetition of the original sound, known as an echo. Echoes occur due to the reflection of sound waves off solid surfaces, and they can alter the perception and quality of the original sound.
A. Kinetic energy
B. Electrical energy
C. Potential energy
D. Chemical energy
Correct Answer: D. Chemical energy
A. Red
B. Yellow
C. Violet
D. Green
Correct Answer: C. Violet
A. Nitrogen
B. Carbon dioxide
C. Hydrogen
D. Oxygen
Correct Answer: A. Nitrogen
A. Force
B. Energy
C. Angular momentum
D. Linear momentum
Correct Answer: C. Angular momentum
A. Acne
B. Eyesight
C. Headache
D. Stomach ache
Correct Answer: D. Stomach ache
A. Petrol
B. Mercury
C. Saltwater
D. Freshwater
Correct Answer: A. Petrol
A. Colour
B. Clarity
C. Resolution
D. Graphics
Correct Answer: C. Resolution
A. 100% Ethyl alcohol
B. 95% Ethyl alcohol
C. Tincture iodine
D. Methylated spirit
Correct Answer: B. 95% Ethyl alcohol
Rectified spirit contains 95% ethanol with 5% water. A rectified alcohol is highly concentrated ethanol that has been purified by means of repeated distillation, a process that is called rectification. It typically contains 95% alcohol by volume and 5 % water. Normally, ethanol with 5 % water is known as pure alcohol.