P5 - Electricity and Magnetism (part 1)

Q1. A polythene rod repels an inflated balloon hanging from a nylon thread. Why do the rod and balloon repel?

• A The rod and the balloon have opposite charges.

• B The rod and the balloon have like charges.

• C The rod is charged but the balloon is not.

• D The balloon is charged but the rod is not.

Q2. A plastic rod and a dry cloth are uncharged. The rod is now rubbed with the cloth and they both become charged. The rod becomes negatively charged because some charged particles move from the cloth to the rod. What is the charge on the cloth and which particles moved in the charging process?

• A
• B
• C
• D

Q3. Two balloons, X and Y, are suspended by insulating threads. They are each held near a negatively charged balloon. The balloons hang as shown. What is the charge on balloon X and what is the charge on balloon Y?

• A Balloon X is negative and Balloon Y is negative
• B Balloon X is negative and Balloon Y is positive
• C Balloon X is positive and Balloon Y is negative
• D Balloon X is positive and Balloon Y is positive

Q4. Three charged balls, P, Q and R are suspended by insulating threads. Ball P is negatively charged. What is the charge on ball R?

• A negative
• B positive
• C zero charge
• D None of them.

Q5. Which group contains only good electrical conductors?

• A Air, carbon, plastics
• B air, gold, mecury
• C carbon, copper, mecury
• D copper, gold, silver

Q6. A bar of soft iron and a bar of steel are held in contact with a strong magnet. Both bars become magnetised The two bars are now moved away from the magnet. Which statement about the bars is correct?

• A Both bars easily lose their magnetism.
• B Neither of the bars easily lose its magnetism.
• C The soft iron bar easily lose its magnetism but the steel bar retains its magnetism.
• D The steel bar easily lose its magnetism but the soft iron bar retains its magnetism.

Q7. Which type of magnet can be swithced on and off many times per second?

• A an electromagnet only
• B a permanent magnet only
• C both electromagnets and permanent magnets
• D neither electromagnets or permanent magnets

Q8. What is meant by an electric field?

• A a region in which a charge experiences a force
• B a region in which a current experiences a force
• C a region in which a magnetic pole experiences a force
• D a region in which a mass experiences a force

Q9. A current is defined as:

• A the rate of flow of water.
• B the rate of flow of charges
• C the rate of flow of any kind of particles
• D None of them.

Q10. Which answer contains only magnetic materials?

• A steel, gold, coban, nickel
• B silver, gold, steel, nickel
• C iron, coban, nickel, steel
• D iron, gold, coban, nickel