Multiple choice 3

The gravitational field strength at the Earth’s North Pole is greater than at the Equator. An object is moved from the Equator to the North Pole. What effect, if any, does this have on the mass and on the weight of the object?

• A

• B

• C

• D

A brick has a mass of 1.5 kg. It rests on the ground and the area of contact with the ground is 0.030 m2 . A stack of such bricks is made by placing the bricks on top of each other, as shown.

The pressure on the ground due to the stack must not exceed 5700Pa. What is the maximum number of bricks that can be made into such a stack? gravitational field strength = 10 N/ kg

• 12

• 114

• 11

• 256

Which equation for kinetic energy (K.E.) is correct?

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A car accelerates uniformly from rest along a horizontal road. After 5.0 s, its kinetic energy is 400 kJ. What is the useful power produced by the engine of the car?

• 2000W

• 80W

• 80000W

• 2000000W

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

• chemical potential energy

• nuclear energy

• elastic potential (strain) energy

• gravitational potential energy

A fixed mass of gas is trapped in a container. The temperature of the gas is increased but the volume of the container does not change. How do the kinetic energy of the molecules and the pressure of the gas change?

• A

• B

• C

• D

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?

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

• a permanent magnet only

• neither electromagnets or permanent magnets

• an electromagnet only

• both electromagnets and permanent magnets

A charge of 480 C passes through a wire in 3.0 minutes. What is the average current in the wire?

• 160A

• 24A

• 1440A

• 2.7A

What is an advantage of connecting lamps in parallel in a circuit, rather than in series?

• The lamps last longer before failing.

• The potential difference (p.d.) across each lamp is smaller.

• The lamps do not use as much energy.

• When one lamp fails, all the others remain lit.