June 2015 Flashcards
1
Q
How could you check that fuses are the correct value?
A
- Ammeter.
- Vary current in fuse.
- Lamp to see if fuse is broke.
2
Q
What can you describe a graph as if it isn’t positive?
A
Relationship is non-linear.
3
Q
Why does someone move back when she throws something?
A
- Momentum is conserved.
- Momentum of snowball and skater are equal and opposite because momentum initially equals 0.
4
Q
How do knee pads protect someone when they fall?
A
- Increased time.
- Same change in momentum.
- Force is rate of change in momentum.
- Reduces force.
5
Q
How does an object get charged by friction?
A
- Rubbing materials.
- Movement of electrons.
- Electrons have negative charge.
6
Q
Why does the core of a transformer need to be a soft magnetic material?
A
- Loses magnetism easily.
- Magnetic field in coil changes.
7
Q
Primary voltage / secondary voltage =
A
Primary turns / secondary turns.
8
Q
ms into s?
A
Divide by 1000.
