Physical Science Pressure, Torque and Electricity

What is the main purpose of a Van de Graaff generator?

• To generate mechanical energy

• To create static electricity

• To produce thermal energy

• To convert solar power

What happens to a person's hair when they touch the dome of an operating Van de Graaff generator?

• The hair becomes wet

• Nothing happens to the hair

• The hair stands straight up

• The hair falls flat

Which type of electrical charge builds up on the dome of a Van de Graaff generator?

• Neutral charge

• Positive charge

• Alternating charge

• Negative charge

What safety precaution should be taken when using a Van de Graaff generator?

• it should be earthed to prevent accidental discharge

• Stand in water

• Touch it constantly

• use devices while touching it

What happens when you rub a plastic rod with wool?

• The plastic rod gains protons

• The plastic rod gains electrons and becomes negatively charged

• The plastic rod loses all its charge

• The plastic rod becomes positively charged

When a glass rod is rubbed with silk, what happens to it?

• It remains neutral

• It becomes negatively charged

• It becomes positively charged

• It loses all electrical properties

Which of the following defines pressure?

• force divide to area

• force multiply by area

• force added to area

• force subtracted to area

Why do sharp knives cut better than dull ones?

• They are made of stronger metal

• They concentrate more pressure on a smaller area

• They are usually newer

• They reflect more light

Which situation demonstrates the highest pressure?

• An elephant standing on all four feet

• A thumbtack point pressed against a wall

• A book lying flat on a table

• A brick standing on its largest face

Which of the following statements best describes how pressure changes with depth in a liquid?

• Pressure decreases as depth increases

• Pressure increases as depth increases

• Pressure remains constant regardless of depth

• Pressure only changes near the surface