Here are the answers to your science revision worksheet.
Q.A) Fill in the blanks by choosing correct option.
1) Sounds of 160 decibels cause
permanent damage to our ears.
*(Reasoning: Very loud sounds like explosions or jet engines can hurt your hearing forever.)*
2) The force of the electricity in a circuit is measured in
volts.
*(Reasoning: Volts measure electrical pressure or force. Metres measure distance.)*
3) The
volume of a sound is how loud or quiet it is.
*(Reasoning: Pitch is how high or low a sound is, like a squeak vs. a rumble. Volume is the loudness.)*
4) Earthquakes are
natural disasters.
*(Reasoning: They happen because of movements in the Earth, not because humans made them.)*
5) An
oscilloscope shows both the pitch and volume of a sound.
*(Reasoning: An oscilloscope draws a picture of sound waves on a screen. A stethoscope is used by doctors to listen to hearts.)*
***
Q.B) State whether the following statements are true or false
1) If you tap the end of the tuning fork it starts to vibrate.
True
*(Reasoning: Hitting the fork makes it shake back and forth quickly, which creates sound.)*
2) Sound can travel through materials and air.
True
*(Reasoning: Sound needs something to travel through, like air, water, or solids like wood.)*
3) Electricity flows in an open circuit.
False
*(Reasoning: "Open" means there is a gap or break in the wire. Electricity needs a complete loop (closed circuit) to flow.)*
***
Q.C) Name the following
1) Sound will not travel through this space. -
Vacuum (or Space)
*(Reasoning: A vacuum has no air or matter for sound waves to move through.)*
2) Device used to measure how loud a sound is. -
Decibel meter (or Sound Level Meter)
*(Reasoning: This tool measures sound intensity in decibels.)*
3) The type of battery used in mobile phones. -
Rechargeable battery (or Lithium-ion battery)
*(Reasoning: Phone batteries can be charged up again and again.)*
4) The type of oil found under the earth. -
Crude oil (or Petroleum)
*(Reasoning: This is the raw oil pumped from the ground before it is turned into fuel.)*
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Final Answer:
Q.A)
1) permanent
2) volts
3) volume
4) natural
5) oscilloscope
Q.B)
1) True
2) True
3) False
Q.C)
1) Vacuum
2) Decibel meter
3) Rechargeable battery
4) Crude oil
Parent Tip: Review the logic above to help your child master the concept of year 4 maths revision worksheet.
