pt1 model paper science Flashcards
sigma (20 cards)
What is the wavelength in a wave diagram?
The distance between two consecutive crests or troughs
Wavelength is typically represented by a specific label in wave diagrams.
Which statement about the two notes sung by a singer is correct?
The first note has a larger amplitude and a smaller frequency than the second note.
Amplitude relates to loudness, while frequency relates to pitch.
What represents the movement of air molecules due to a sound wave?
The diagram showing the compression and rarefaction of air molecules.
This is typically illustrated in sound wave diagrams.
Assertion: Sound waves can travel through a vacuum. Reason: Sound waves are mechanical waves and require a medium for propagation. What is the correct option?
d) A is false but R is true.
Sound cannot travel through a vacuum as it needs a medium.
What can be concluded about the amplitude and frequency of sound wave N compared to sound wave M?
Sound wave N has a larger amplitude and the same frequency as sound wave M.
Loudness is associated with amplitude, while pitch is related to frequency.
List any 4 measures to reduce noise pollution.
- Restrict the use of loudspeakers
- Use effective silencers in vehicles
- Maintain machinery and appliances
- Separate industrial and residential areas
These measures aim to minimize sound disturbances in the environment.
What is the frequency of the sound wave produced by Riya’s tuning fork?
500 Hz
Frequency is calculated as the number of cycles per second.
Calculate the time period of the wave produced by Riya’s tuning fork.
0.002 seconds
Time period is the inverse of frequency.
Define amplitude and state its value in Riya’s experiment.
Amplitude is the maximum displacement from the mean position, which is 3 cm in Riya’s experiment.
Amplitude affects the loudness of sound.
If Riya increases the amplitude of the wave, what property of the sound will change?
The loudness of the sound will increase.
Amplitude is directly related to the energy and loudness of the sound.
What synthetic plastic is used for making insulation cover in electrical wires?
Polyvinylchloride
PVC is commonly used for insulation due to its durability.
Identify the synthetic plastics X, Y, and Z.
X- Melamine, Y- Teflon, Z- Bakelite
These plastics have different applications based on their properties.
Assertion: Thermosetting plastics cannot be remoulded. Reason: Thermosetting plastics can change their shape even after providing sufficient heat. What is the correct option?
iii. A is true but R is false.
Thermosetting plastics cannot be reshaped once set.
What are blended fibres?
Blended fibres are made by mixing a natural fibre and a synthetic fibre to enhance strength and comfort.
An example is poly-cotton.
Identify P, Q, R, and S in Anmol’s flowchart on fibres and plastics.
P- animal fibre, Q- plant fibre, R- thermosetting plastic, S- thermoplastic
This classification helps in understanding the properties and uses of different materials.
Differentiate between metals and non-metals based on physical properties.
- Metals are lustrous, malleable, ductile, and good conductors of heat and electricity
- Non-metals are not lustrous, non-malleable, non-ductile, and poor conductors of heat and electricity.
These differences influence their applications in various fields.
Which fibre is known as artificial silk and why?
Rayon is known as artificial silk due to its similar properties to silk.
It is often used as a substitute for silk in textiles.
Differentiate between biodegradable and non-biodegradable materials.
- Biodegradable materials decompose naturally
- Non-biodegradable materials do not decompose easily.
This classification is important for environmental management.
What is the chemical method of controlling pests?
It uses chemical pesticides for quick action against various pests but can contaminate the environment.
This method contrasts with natural methods that utilize biological control.
What is denitrification?
The process where denitrifying bacteria convert nitrates in the soil into nitrogen gas, releasing it into the atmosphere.
This process is crucial for maintaining nitrogen balance in ecosystems.
