Practice Exercise
1. Which among the
following is the best insulator?
(a) Wood (c) Dry air
(b) Glass (d) Cloth
2. The one that is a good conductor of electricity in the
following list of solids is
(a) Graphite
(b) diamond
(c) sodium fluoride
(d) sodium chloride
3 A good conductor while carrying current is
(a) negatively charged
(b) positively charged
(c) electrically neutral
(d) alternately charged positive and negative
(a) Coulomb
(b) Candela
(c) Fathom
(d) Hertz
5. An electric current can produce
(a) heating effect
(b) chemical effect
(c) magnetic effect
(d) chemical, heating and magnetic effect
6. On passing electric current through solution of an
electrolyte the solution experiences
(a) magnetic effect
(a) heating effect
(c) chemical effect
(d) None of the above
7. An electrical quantity is defined as the energy converted
by a source in driving a unit charge in a complete circuit. What is this
quantity called?
(a) Current
(b) Electromotive force
(c) Power
(d) Potential difference
8. Alternating current is converted to direct current by
(a) rectifier
(b) dynamo
(c) transformer
(d) motor
9. Which of the following metals is used in electroplating
to make
(a) Iron (b) Copper
(c) Chromium
(d) Aluminum
10. For electroplating nickel on an object, which terminal
of the battery is connected to the object
(a) positive (b) negative
(c) Both (a) and (b) (d) None of the above
11. What is measured by galvanometer?
(a) It meastires the electric current of low magnitude
(b) It measures the specific gravity of liquids
(c) It measures sound under water
(d) It measures electricity
12. The device used for converting energy is called a/an.
(a) Cell
(b) Transformer
(c) Dynamo
(d) Electric motor
13. What is the source of elecric in an artificial
satellite?
(a) A mini nuclear reactor (b) A dyanamo
(c) A thermopile (d) Solar cells
14. Transformer is a kind of appliance that can?
(a) increase power
(b) Increase voltage
(c) decrease voltage
(d) measure current and voltage
circuit
(a) reduces substantially
(b) does not change
(c) increases heavily
(d) varies
continuously
16. The output of a dynamo using a split ring commutator is
objects appear shining?
(a) fluctuating DC (b) AC
(c) DC (d)
half wave rectified voltage
17. All the magnetic materials lose their magnetic
properties when
(a) dipped in oil (b) dipped in water
(c) strongly heated (d) brought near a piece of iron
18. Permanent magnets can be made from
(a) cobalt (c) zinc
(b) aluminium (d) lead
19. The magnetic lines of force inside a bar magnet flow
(a) from North pole to South pole
(b) from South pole to North pole
(c) from both North and South poles to the middle point of
the bar magnet
(d) from North or
South poles, depending on the place and direction in which the bar magnet is
placed mechanical energy into electrical
20. A substance consisting of a coil of wire with an iron
core and is only magnetised when an electric current flows through it is called
(a) magnet (b)
electromagnet
(c) battery (d) coil
Answers- 1. (a) 2.
(b) 3. (c) 4. (a)
5.(d) 6. (c) 7. (b)
8. (a) 9. (c) 10. (b)
11.
(a) 12. (c) 13. (d) 14. (b,c)
15. (c) 16. (a) 17. (c)
18. (a) 19. (b) 20. (b)
