Available Answers

1. 1.

   Write true or false. Correct the false statements.

   1. When a glass rod is rubbed with a silk cloth, the glass rod acquires a negative charge.
   2. A metal rod can be charged if an ebonite rod rubbed with woollen cloth is brought near it.
   3. A conductor held in hand can be charged by rubbing it with a silk cloth.
   4. Two balloons rubbed with hair will attract each other.
   5. If an object transfers its electrons to another object, it becomes negatively charged.
2. 2.

   Fill in the blanks.

   1.  An electroscope can be used to detect the presence of _______________________
   2. The gold leaves of an uncharged electroscope _____________________ if a charged body is brought in contact with its brass disc.
   3. A ___________________________ is used to prevent a tall building from damage from a lightning strike.
   4. _____________________ is a high-energy electric discharge.
   5. An electroscope can be charged by either of the two ways, _____________________
3. 3.

   Tick the most appropriate answer.

   1. Which of the following is a non-conductor of electricity?

   1. silver
   2. copper
   3. plastic
   4. aluminium

   2. An electroscope is an instrument used to

   1. detect the presence of charge on a body.
   2. view electrons.
   3. produce an electrostatic charge.
   4. view atoms.

   3. If an electroscope is charged by induction, it acquires

   1. the same charge.
   2. an opposite charge.
   3. no charge at all.
   4. none of these.

   4. Transferring a charge by touching is called charging by

   1. conduction.
   2. induction.
   3. convection.
   4. radiation.

   5. Moving charges constitute

   1. electrode.
   2. induction.
   3. convection.
   4. radiation.

   6. The colour code for a live wire is

   1. black or blue.
   2. green or yellow.
   3. red or brown.
   4. white and black.

   7. The top think pin of a plug is always connected to the

   1. live wire.
   2. neutral wire.
   3. earth wire.
   4. fuse wire.

   8. An electric fuse is always connected to the

   1. live wire.
   2. neutral wire.
   3. earth wire.
   4. fuse wire.

   9. The consequence of improper handling of electricity is

   1. electric shock.
   2. fire.
   3. both a and b
   4. none of these

   10. A battery is a collection of cells in

   1. series.
   2. parallel.
   3. random order.
   4. none of these
4. 4.

   Fill in the blanks.

   1. Matter is made of tiny particles called _______________________________.
   2. When an atom loses electrons, it acquires a net _______________________ charge.
   3. An electroscope can be used to test whether a body is a _______________________ or not.
   4. When a positively charged body is brought near a conductor, it induces a ________________________ charge on the near end of the conductor.
   5. A lightning conductor is a long rod made of either ________________ or _________________.
   6. In an electric circuit, the __________________________ wire carries all the current.
   7. The bigger hole in a socket called _______________________ saves us from getting electric shocks.
   8.  An electric meter measures the amount of electricity consumed in units of _________________________.
   9. The flow of large amount of current through a circuit due to the contact between the live and the neutral wire is called _________________________.
   10.  The melting point of a fuse wire is __________________________ than the melting point of the connecting wires.
5. 5.

   Write true or false. Correct the false statements.

   1. Neutrons are present inside the nucleus of an atom.
   2. Charges can be exchanged between two bodies by friction.
   3. The force of attraction or repulsion between two charged bodies is called gravitational force.
   4. The leaves of a gold-leaf electroscope are made of brass.
   5. Lightning is caused due to discharge between similarly charged clouds.
   6. The cables that bring electricity to our homes consist of five wires.
   7. Electric meters measure the consumption of energy in joules.
   8. Miniature circuit breakers act as safety devices.
6. 6.

   How is a body charged by friction?