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CLASS 10 SCIENCE SAMPLE QUESTION CH-MAGNETIC EFFECT OF CURRENT
CLASS 10 SCIENCE SAMPLE QUESTION CH-MAGNETIC EFFECT OF CURRENT
SOME IMPORTANT QUESTION
1. Q. What is solenoid? Draw the
pattern 0f magnetic field line of a solenoid through which steady current flows 2 Marks
2. Q. What are permanent magnet
and electromagnet? Give two use of each. 2 Marks
3. Q. Differentiate short circuit
and over loading? 2 Marks
4. Q. Draw the pattern of
magnetic field lines of produce by current carrying circular loop 2 Marks
5. Q. What is role of fuse in
domestic circuit? Why we use the fuse of defined rating not be replaced by one
with large rating? 2 Marks
6. Q. How will deflection of
compass get affected if current in straight wire is increased? support your
answer with reason? 2 Marks
7. Q. No two field line intersect
each other . Explain? 2 Marks
8. Q. What is the direction of
thumb indicates in right hand thumb rule? In what way this rule is different
from Fleming’s left hand rule? 2 Marks
9. Q. Why does a current carrying
conductor kept in a magnetic field experience force? On what factor does the
direction of this force depend? Name and state the rule used determination of
direction of current? 2 Marks
10. Q. Two circular coil A and B
placed closed to each other If the current in coil A is changed, will some
current be induced in the coil B? Give reason? 2 Marks
11. Q. What do you mean by term
magnetic field line? List any two properties? 2 Marks
12. Q. Give an activity to show
magnetic field produce by current carrying circular loop? 2 Marks
13. Q. What precautions should be
taken to avoid the overloading of domestic circuit? 2 Marks
14. Q. Why do we connect earth
wire in house give two reason? 2 Marks
15.Q. Write four properties of
magnetic field lines? 2 Marks
MAGNETIC EFFECTS OF ELECTRIC
CURRENT
PRE YEAR QUESTION
1. Name the type of current. (a) used in
household supply (b) given in cell (CBSE (CCE) 2011)
2. Name the physical quantities of
electromagnetic induction. (CBSE (CCE) 2012)
3. Give one application of electromagnetic
induction. (CBSE (CCE) 2012)
4. Name any two appliances which are based on
the application of heating effect of electric current. (AI 2009C)
5. What constitutes the field of a magnet?
(DELHI 2006)
6. A compass needle is placed near a current
carrying wire. State your observation for the following cases, and give reason
for the same in each case.
a. Magnitude of electric current
in the wire is increased
b. The compass needle is
displayed away from the wire. (CBSE (CCE) 2012)
7. Explain the role of fuse in series with any
electrical appliance in an electric circuit. Why should a fuse with defined
rating for an electric circuit not be replaced by one with a larger rating?
(CBSE (CCE) 2011)
8. What is meant by the term frequency of an
alternating current? What is the value in India? Why is an alternating current
considered to be advantageous over direct current for long range transmission
of electric energy? (CBSE SAMPLE PAPER 2009)
9. What is an electromagnet? Draw a circuit
diagram to show how a soft iron piece can be transformed into electromagnet.
(DELHI 2008)
10. With the help of neat diagram describe how
you can generate induced current in the circuit. (DELHI 2006C)
11. a. Mention effect of electric current on
which the working of an electrical fuse is based.
b. Draw a schematic labeled diagram
of a domestic circuit which has a provision of a main base, meter, one light
bulb and a socket.
c. Explain the term overloading of an
electric circuit. (CBSE (CCE) 2012)
12. a. Describe an activity to demonstrate the pattern
of magnetic field lines around a straight conductor carrying current.
b. State the rule to find the
direction of magnetic field associated with a current carrying conductor?
c. What is the shape of a current
carrying conductor whose magnetic field pattern
MAGNETIC
EFFECTS OF ELECTRIC CURRENT
1. The MCB of a Rupa’s room is tripped and keeps
on tripping again and again. If it is a domestic circuit, what could be the
reason of this phenomenon?
2. State any three appliances that function on
Fleming’s left hand rule.
3. What is the need to convert Dynamo into
alternating current?
4. Find the applications of solenoid.
5. Difference between short circuiting and
overloading.
6. Show an activity to demonstrate the direction
of the magnetic field generated around a current carrying conductor.
7. What is a fuse? What material is used for
make fuse wire?
8. State the properties of magnetic lines of
force.
9. Name two safety measures commonly used in
electric circuits and appliances.
10. What is the direction of magnetic field in
bar magnet?
SHORT
QUESTIONS
ANSWER IN
SHORT:
1.Who
provided the first evidence of connection between electricity and magnetism ?
When ?
ANS :Danish physicist H.C.Oersted in 1820 AD
provided the first evidence of connection between electricity and magnetism.
2.Why is a
magnetic needle placed near a current carrying conductor deflected ?
ANS : A
magnetic needle placed near a current carrying conductor is deflected because
the current carrying conductor possesses a magnetic field.
3.State the
Right-hand Thumb Rule.
ANS : Hold
the conducting wire in the right hand such that the thumb is stretched along
the direction of the current, then the fingers will wrap around the conductor
in the direction of the magnetic field.
4.What is a
solenoid?
ANS : A coil of many turns of wire wrapped in
the shape of a cylinder is called a solenoid.
5.What is
'induced electric current'?
ANS : The electric current produced in a loop
of conductor due to the relative motion of a magnet within the loop(coil) is
called induced electric current.
6.What is
electromagnetic induction ?
ANS : Electromagnetic induction is the
production of electromotive force(voltage) in a conductor when there is
relative motion of the conductor within a magnetic field.
7.What is an
electric motor ?
ANS : An
electric motor is a device that converts electrical energy into mechanical
energy.
8.Write the
principle of electric motor.
ANS : An electric motor converts electrical
energy into mechanical energy by using the principle that in an electric field
the current-carrying conductor experiences force.
9.What is an
armature ?
ANS : A
loop(coil) wound on an axis along with the commutator is known as an armature.
10.Name some
gadgets where an electric motor is used.
ANS : Fan,
mixer, washing machine, fridge, water pump, etc.are examples of gadgets where
an electric motor is used.
11.What is
an electric generator ?
ANS : An
electric generator is a device which converts mechanical energy into electrical
energy.
12.On which
principle does an electric generator work ?
ANS : An
electric generator works on the principle of electromagnetic induction.
13.Mention
two types of current.
ANS : The
two types of current are :(i) Direct Current, DC (ii) Alternating Current, AC.
14.What is
direct current ?
ANS : If in
a circuit, the current flows from the positive terminal to the negative
terminal(i.e. only in one direction) of the battery, the current is called
direct current(DC).
15.What is
alternating current ?
ANS : If in
a circuit the voltage and current change their direction between positive and
negative terminals periodically with the time, the current is called alternating
current(AC).
16.Which
type of current is supplied/used in domestic lines ?
ANS :
Alternating current(AC) is supplied in domestic lines.
17.What do
we mean by frequency of current ?
ANS : The number of times an alternating
current in a circuit changes its direction per second is called the frequency
of that current.
18.What is
the unit of frequency of current ?
ANS :
'Hertz' (Hz) is the unit of frequency of current.
19.What is
the colour of insulation cover of a 'live wire' or 'phase wire'?
ANS : Red is
the colour of insulation cover of a 'live wire' or 'phase wire'.
20.Mention
the colour of insulation cover of a 'neutral wire' or 'negative wire'.
ANS : The
colour of insulation cover of a 'neutral wire' is black.
21.To what
is the earth wire connected ?
ANS : The earth wire is connected to a metal
plate deep in the earth near the house.
22.Which is
the type of connection used for domestic wiring ?
ANS : The
type of connection used for domestic wiring is parallel connection.
23.How is an
inductor shown in a circuit ?
ANS : ΩΩΩ is
the symbol to show an inductor in a circuit.
24.What does
short-circuit mean ?
ANS :
Short-circuit means the positive and negative wires have come into contact with
each other due to some fault.
25.What is
overloading ?
ANS :
Overloading is the situation created when many appliances connected in a
circuit draw much higher current than the electric line can hold.
26.What is a
fuse ?
ANS : A fuse
is a device consisting of a wire made up of a low melting-point metal/alloy
which melts during short-circuit or overloading and prevents accident as well
as damage to costly appliances.
27.Which
metal is generally used to make a fuse wire ?
ANS : Fuse
wires are generally made up of pure tin or an alloy of tin with other metals
like copper.
28.What type
of magnetic field arises when current passes through a linear wire ?
ANS : A
circular magnetic field( or a field comprising of concentric circles) arises
around a linear wire when current passes through it.
29.In which
part of solenoid do we find uniform magnetic field ?
ANS : We
find uniform magnetic field in the central(core) part of a solenoid.
30.What is
an electromagnet ?
ANS : An iron bar(core) with coils of wire
wound around it,which acts as a temporary magnet when an electric current flows
through the wire is called ELECTROMAGNET.
31.When will
the current carrying wire experience maximum force in the magnetic field ?
ANS :When it
is placed perpendicularly to the magnetic field.
32.The
frequency of alternating current is 50 Hz. What does it mean ?
ANS :It means that the current changes its
direction alternately 50 times between two terminals in one second.
Magnetic Effects of Electric Current Class
10 CBSE Important Question and Answers
Q1.State the factors on which strength of
magnetic field at a point due to a current carrying conductor depends?
Ans. The factors on which strength of a magne tic field at a point depends.
(1) Amount of current (I) flowing through the conductor
(2) Distance (r) from the current carrying conductor.
Q2.What is an electromagnet? Write two uses of an e lectromagnet?
Ans.When current is passed through a solenoid it behaves as a magnet and is called as an electromagnet. The two uses of an electromagnet are-
(1) They are used to lift heavy iron pieces.
(2) They are used in many devices like micro phone, rad io sets, electric bell etc.
Q3.tate and define S.I unit of magnetic field?
Ans. The S.I unit of magnetic field is Tesla ( T). The magnetic field strength is said to be one Tesla if 1 meter long conductor carrying 1 ampe re current experiences 1 Newton force, when placed perpendicular to the dire ction of magnetic field.
Q4. current carrying conductor is placed perpendic ular to the uniform magnetic field. What happens to displacement of the conducto r if
(i) strength of current increases
(ii) If horse shoe magnet is replaced by a weak hor se shoe magnet.
Ans. The displacement of the conductor
(i) will increase on increasing the current
(ii) Will decrease on using a weak horse shoe magnet.
Q5.Define electromagnetic induction? Two circular coils A and B are placed close to each other. If the current in the coil A is changed , will some current be induced in the coil B? Explain.
Ans.Electromagnetic induction means the product ion of induced current in a closed coil due to the change in the magnetic field. When current in coil A is changed, magnetic flux sets up around coil A due to which some magnetic field set up in the coil B thus some induced current flow through coil B due to which galvanometer deflects.
Q6.Why does a current carrying conductor kept in a magnetic field experience force? What is the direction of force acting on the conductor?
Ans.A current carrying coil contains charged pa rticles which experiences a force (Bqv). The total force experienced by the charged particle is equal to the force experienced by the conductor which is perpendicular to both the magnetic field and the direction of current in the conductor.
Q7. (a) Distinguish between A.C and D.C?
(b) Which source produces alternating current?
Ans. Q8. (a) Define the term current rating of an electr ic fuse?
(b) Name the material used to make electric fuse?
(c) Name two safety measure commonly used in electr ic circuit and appliances?
Ans. (a) The maximum amount of current that can be passed through the fuse wire without melting it.
(b) Copper or alloy of lead acid tin
. (c) Electric fuses and earth wire.
Q9.Why do not two magnetic fie ld lines intersect each other?
Ans. The two magnetic field lines never intersec t each other because at the point of intersection there will be two directions of magnet ic field, which is not possible.
Q10,Name and state rule used to determine the direction of magnetic field produced around a straight conductor carrying current?
Ans. The rule is known as right hand thumb rule if a current carrying conductor is held in our right hand such that thumb points in the direction of current, then the curled fingers of the hand indicate the direction of magnetic field.
Q11.What is a soleno id? Draw magnetic field lines showing the magnetic field inside and outside the current carrying solenoid? Ans.A solenoid is a coil of many turns of insulated copper wire closely wound in the shape of a ring.
Q12.(a) Name f our appliances wherein an electric motor is used as an important component. In what respect it is different from gen erator?
(b) Define the terms used in the generator (i) armature (ii) slip rings (iii) brushes
Ans.The four appliances which have electric mot or inside them are (i) Mixers (ii) Washing machine (iii) Refrigerators (iv) Blenders
(i) Armature – Armature is a coil of large number of turns of insu lated copper wire wound over a soft iron core.
(ii) Slip rings- Slip Rings one two ring s made up of brass which rotates along with the coil.
(iii) Brushes- Brushes are made up of carb on which are pressed against the slip rings and are connected to external circuit where output is obtained.
Q13.(a) What is the standard colour code followed for (i) live (ii) neutral and (iii) earth wires used in electric ci rcuits?
(b) Which part of an electric appliance is earthed and why?
Ans.(a) The standard colour code for Live wire- Red Neutral- Black Earth- Green r espectively.
(b) The metallic case of an electrical appliance i s earthed because metals are good conductors of electricity and in case if curre nt exceeds i.e. live wire touches the metallic case of an appliance and then due to earthing all the excess amount of current flows down to the earth an d we prevent ourselves from an electric shock.
Q14.(a) What is short circuiting?
(b) What is overloading? How can you avoid overload ing?
Ans.a) Short circuiting means when live wire and the neutral wires come in contact with each other. Due to this resistance of the circ uit becomes very small and huge amount of current flows through the circuit wh ich is turn produces more heat which can cause fire.
(b) Overloading means large amount of current flows in the circuit. It can happen when many electrical appliances of high power ratin gs are connected in a single socket. It can be avoided by the following m ethods
(i) Not use too many appliance is a single socket
(ii) To apply preventive methods of short circuiting.
Q15.E xplain the principle, construction and working of a n electric motor with a help of labelled diagram?
Ans. Principle – it is based on the principal that a current carrying conductor placed perpendicular to the magnetic field experiences a f orce.
Construction- (1) Armature or coil- It consist of an insulated c opper wire wound on a soft iron core.
(2) Strong field magnet- two pole pieces of a stro ng magnet provides a strong magnetic field.
(3) Split ring- it consist of two halves 1 2 ( and R ) R of a metallic ring which reverses the direction of the current in a coil.
(4) Brushes- two carbon brushes touch the commutat or (split ring). (5) Battery – a battery is connected across the ca rbon brushes.
Q16.State two properties of magnetic lines of force?
Ans. (i) Magnetic lines of force are cl osed continuous curves.
(ii) The tangent at any point on the magnetic line of fo rce which gives the direction of magnetic field at that point.
Q17.Why does a compass needle deflected when brought ne ar a bar magnet ?
Ans. Compass needle experience a force is the magnetic field of a bar magnet due to which it deflects.
Q17.Write two ways to induce current in a coil?
Ans.) By moving a bar magnet toward or awa y from the coil.
(ii) By placing a coil near another coil connected across a battery.
Q18.What is the function of an earth wire? Why is if ne cessary to earth metallic casing of electric appliance?
Ans.Earth will acts as a safety device. Whe n live wire touches the metallic appliance then electric current flows through castling to the earth instead of human body and thus we prevent ourselves from getting shock. I t is necessary to earth metallic casing of the appliance because it saved e lectrical appliance from burning and prevent us from electric shock.
Q19.We know a current carrying conductor placed in a ma gnetic field experiences a force due to which the conductor moves. How do we t hink the rod displaces if- (a) current in rod is increased (b) a stronger horse shoe is inserted (c) length of the rod is increased.
Ans. Force acting on current carrying condu ctor F=BIL (a) When I increase, F also increases hence displacemen t of the rod increases.
(b) When a stronger horse shoe magnet is inserted, magn etic field B increases. So force F increase. Hence displacement increases.
(c) When I increases, force increases and hence displac ement increases.
Q20.
Ans. The factors on which strength of a magne tic field at a point depends.
(1) Amount of current (I) flowing through the conductor
(2) Distance (r) from the current carrying conductor.
Q2.What is an electromagnet? Write two uses of an e lectromagnet?
Ans.When current is passed through a solenoid it behaves as a magnet and is called as an electromagnet. The two uses of an electromagnet are-
(1) They are used to lift heavy iron pieces.
(2) They are used in many devices like micro phone, rad io sets, electric bell etc.
Q3.tate and define S.I unit of magnetic field?
Ans. The S.I unit of magnetic field is Tesla ( T). The magnetic field strength is said to be one Tesla if 1 meter long conductor carrying 1 ampe re current experiences 1 Newton force, when placed perpendicular to the dire ction of magnetic field.
Q4. current carrying conductor is placed perpendic ular to the uniform magnetic field. What happens to displacement of the conducto r if
(i) strength of current increases
(ii) If horse shoe magnet is replaced by a weak hor se shoe magnet.
Ans. The displacement of the conductor
(i) will increase on increasing the current
(ii) Will decrease on using a weak horse shoe magnet.
Q5.Define electromagnetic induction? Two circular coils A and B are placed close to each other. If the current in the coil A is changed , will some current be induced in the coil B? Explain.
Ans.Electromagnetic induction means the product ion of induced current in a closed coil due to the change in the magnetic field. When current in coil A is changed, magnetic flux sets up around coil A due to which some magnetic field set up in the coil B thus some induced current flow through coil B due to which galvanometer deflects.
Q6.Why does a current carrying conductor kept in a magnetic field experience force? What is the direction of force acting on the conductor?
Ans.A current carrying coil contains charged pa rticles which experiences a force (Bqv). The total force experienced by the charged particle is equal to the force experienced by the conductor which is perpendicular to both the magnetic field and the direction of current in the conductor.
Q7. (a) Distinguish between A.C and D.C?
(b) Which source produces alternating current?
Ans. Q8. (a) Define the term current rating of an electr ic fuse?
(b) Name the material used to make electric fuse?
(c) Name two safety measure commonly used in electr ic circuit and appliances?
Ans. (a) The maximum amount of current that can be passed through the fuse wire without melting it.
(b) Copper or alloy of lead acid tin
. (c) Electric fuses and earth wire.
Q9.Why do not two magnetic fie ld lines intersect each other?
Ans. The two magnetic field lines never intersec t each other because at the point of intersection there will be two directions of magnet ic field, which is not possible.
Q10,Name and state rule used to determine the direction of magnetic field produced around a straight conductor carrying current?
Ans. The rule is known as right hand thumb rule if a current carrying conductor is held in our right hand such that thumb points in the direction of current, then the curled fingers of the hand indicate the direction of magnetic field.
Q11.What is a soleno id? Draw magnetic field lines showing the magnetic field inside and outside the current carrying solenoid? Ans.A solenoid is a coil of many turns of insulated copper wire closely wound in the shape of a ring.
Q12.(a) Name f our appliances wherein an electric motor is used as an important component. In what respect it is different from gen erator?
(b) Define the terms used in the generator (i) armature (ii) slip rings (iii) brushes
Ans.The four appliances which have electric mot or inside them are (i) Mixers (ii) Washing machine (iii) Refrigerators (iv) Blenders
(i) Armature – Armature is a coil of large number of turns of insu lated copper wire wound over a soft iron core.
(ii) Slip rings- Slip Rings one two ring s made up of brass which rotates along with the coil.
(iii) Brushes- Brushes are made up of carb on which are pressed against the slip rings and are connected to external circuit where output is obtained.
Q13.(a) What is the standard colour code followed for (i) live (ii) neutral and (iii) earth wires used in electric ci rcuits?
(b) Which part of an electric appliance is earthed and why?
Ans.(a) The standard colour code for Live wire- Red Neutral- Black Earth- Green r espectively.
(b) The metallic case of an electrical appliance i s earthed because metals are good conductors of electricity and in case if curre nt exceeds i.e. live wire touches the metallic case of an appliance and then due to earthing all the excess amount of current flows down to the earth an d we prevent ourselves from an electric shock.
Q14.(a) What is short circuiting?
(b) What is overloading? How can you avoid overload ing?
Ans.a) Short circuiting means when live wire and the neutral wires come in contact with each other. Due to this resistance of the circ uit becomes very small and huge amount of current flows through the circuit wh ich is turn produces more heat which can cause fire.
(b) Overloading means large amount of current flows in the circuit. It can happen when many electrical appliances of high power ratin gs are connected in a single socket. It can be avoided by the following m ethods
(i) Not use too many appliance is a single socket
(ii) To apply preventive methods of short circuiting.
Q15.E xplain the principle, construction and working of a n electric motor with a help of labelled diagram?
Ans. Principle – it is based on the principal that a current carrying conductor placed perpendicular to the magnetic field experiences a f orce.
Construction- (1) Armature or coil- It consist of an insulated c opper wire wound on a soft iron core.
(2) Strong field magnet- two pole pieces of a stro ng magnet provides a strong magnetic field.
(3) Split ring- it consist of two halves 1 2 ( and R ) R of a metallic ring which reverses the direction of the current in a coil.
(4) Brushes- two carbon brushes touch the commutat or (split ring). (5) Battery – a battery is connected across the ca rbon brushes.
Q16.State two properties of magnetic lines of force?
Ans. (i) Magnetic lines of force are cl osed continuous curves.
(ii) The tangent at any point on the magnetic line of fo rce which gives the direction of magnetic field at that point.
Q17.Why does a compass needle deflected when brought ne ar a bar magnet ?
Ans. Compass needle experience a force is the magnetic field of a bar magnet due to which it deflects.
Q17.Write two ways to induce current in a coil?
Ans.) By moving a bar magnet toward or awa y from the coil.
(ii) By placing a coil near another coil connected across a battery.
Q18.What is the function of an earth wire? Why is if ne cessary to earth metallic casing of electric appliance?
Ans.Earth will acts as a safety device. Whe n live wire touches the metallic appliance then electric current flows through castling to the earth instead of human body and thus we prevent ourselves from getting shock. I t is necessary to earth metallic casing of the appliance because it saved e lectrical appliance from burning and prevent us from electric shock.
Q19.We know a current carrying conductor placed in a ma gnetic field experiences a force due to which the conductor moves. How do we t hink the rod displaces if- (a) current in rod is increased (b) a stronger horse shoe is inserted (c) length of the rod is increased.
Ans. Force acting on current carrying condu ctor F=BIL (a) When I increase, F also increases hence displacemen t of the rod increases.
(b) When a stronger horse shoe magnet is inserted, magn etic field B increases. So force F increase. Hence displacement increases.
(c) When I increases, force increases and hence displac ement increases.
Q20.