Forces

Which of the following statement(s) is/are true about magnetic force?

• A magnet can attract objects made of metal

• The force of a magnet is strongest at its poles

• Magnetic force is a pull or push force exerted by a magnet on another magnetic object

When a bar magnet is brought near object X, it repels. What can object "X" be?

• Iron rod

• Copper bar

• Steel bar

• Bar magnet

Bala sets up an experiment as shown below to find out whether an object produces greater friction when it moves over a wooden surface or a leather surface.

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Study the classification chart above.

• A and C

• A and D

• B and C

• B and D

Which of the following statements about the tyres below is true?

• Tyre A is likely to skid on a wet road

• Tyre B is likely to skid on a wet road

• Tyre A is likely to skid on both wet and dry roads

• Tyre B is likely to skid on a wet road

In a hovercraft, the friction is reduced by ___________.

• The use of lubricants

• A smooth surface

• Floating in the air

• The use of wheels

Which of the following does not measure force?

• A kitchen scale

• An extended spring balance

• A compression spring balance

• A beam balance

Which of the following statements are always true about frictional force?

• Friction will be greater if the two surfaces are rough

• Friction can produce heat

• Friction is always useful to us

• Friction can cause wearing out

The diagram above shows some effects which are due to the same force. What is the force

• Weight

• Gravity

• Speed

• Friction

The picture below shows a man trying to slide a heavy box along the floor.

Which of the following forces would help the man move the heavy box along the floor?

• The mass of the heavy box

• The push the man exerted against the box

• The friction between the box and the floor

• The friction between the man's feet and the floor