Multiple choice 2

A rock has a mass of 360 g. A large measuring cylinder contains 500 cm3 of water. The rock is now lowered into the water and completely submerged. The water level in the measuring cylinder rises to 650 cm3 . Which calculation gives the density of the rock?

• 360÷150 g/cm³

• 360÷150 g/cm³

• 360x150 g/cm³

• 360x650 g/ cm³

• 56N

• 70N

• 47N

• 280N

A force acting on an object increases the kinetic energy of the object from 20 J to 50 J in 5.0 s. What is the average power produced by the force?

• 4.0W

• 6.0W

• 10W

• 14W

From which type of energy is electrical energy transferred in a hydroelectric power station?

• elastic potential (strain) energy

• gravitational potential energy

• chemical potential energy

• nuclear energy

The liquid in a liquid-in-glass thermometer is replaced with a different liquid that expands more for the same increase in temperature. The scale on the thermometer is changed because of the new liquid. What happens to the sensitivity and what happens to the range of the thermometer?

• A

• B

• C

• D

One cause of air movement in the atmosphere is convection. Which statement describes air that rises in the atmosphere due to convection?

• It is warmer and more dense than the surrounding air.

• It is cooler and less dense than the surrounding air.

• It is cooler and more dense than the surrounding air.

• It is warmer and less dense than the surrounding air.

The critical angle for diamond in air is 25. Light travels faster in air than in diamond. Which diagram shows the path of light passing from diamond into air?

• A

• B

• C

• D

The speeds of sound in three different states of the same substance are 480 m / s, 1500 m / s and 1800 m / s. Which row gives the state for each of these speeds?

• A

• B

• C

• D

Which type of magnet can be switched on and off many times per second?

• a permanent magnet only

• both electromagnets and permanent magnets

• an electromagnet only

• neither electromagnets or permanent magnets

A plastic rod is rubbed with a cloth causing a negative charge on the rod. Which statements are correct?

1 The rod gains electrons.

2 The cloth loses electrons.

3 The cloth becomes positively charged.

• 1 and 2 only

• 1 and 3 only

• 2 and 3 only

• 1, 2 and 3