P4: Radiation for Life

Question 1

How can an insulating material become electrically charged?

Answer 1

If it is rubbed with another insulating material. This charge is called static electricity - the electricity stays on the material and does not move. This is due to the transfer of electrons.

Question 2

2 insulating materials with the same charge will do what to each other?

Answer 2

They will repel each other.

Question 3

Two insulating materials with different charges will do what to each other?

Answer 3

Attract each other.

Question 4

Current, Voltage and resistance are related by what formula?

Answer 4

Resistance = Voltage (V) divided by Current (A)

Question 5

What equation is used to choose the correct fuse?

Answer 5

Power (W) = Voltage (V) x Current (A)

Question 6

Ultrasound is the name given to sound waves that have frequencies higher than how many hertz?

Answer 6

20,000 Hertz (Hz) i.e. above the upper threshold of the human hearing range.

Question 7

Ultrasound travels in what kind of waves?

Answer 7

Longitudinal.

Question 8

What are the key features of waves?

Answer 8

Amplitude (Maximum disturbance caused by a wave)
Wavelength (Distance between corresponding points on 2 successive disturbances, e.g. 2 compressions)
Frequency (The number of waves produced (or pass a particular point) in 1 second).

Question 9

Radiation can be given out in what 3 forms of radiation?

Answer 9

Alpha, Beta and Gamma.
Alpha is like a helium nucleus, i.e. 2 Protons and 2 Neutrons.
A Beta particle is a fast-moving electron.
A Gamma Ray is an electromagnetic wave.

Question 10

Is background radiation natural or not in our environment?

Answer 10

Natural.

Most radioactive substances are released by soil and rocks.