Q1.
A soft iron bar is inserted inside a current-carrying solenoid. The magnetic field inside the solenoid:
(a) Will decrease
(b) Will increase
(c) Will become zero
(d) Will remain the same
Q2.
A current carrying conductor is held in exactly vertical direction. In order to produce a clockwise magnetic field around the conductor when viewed from the top, the current should be passed in the conductor:
(a) From top to bottom
(b) From left to right
(c) From bottom to top
(d) From right to left
Q3.
A current flows in a wire running between the S and N poles of a magnet lying horizontally as shown in the figure below. The force on the wire due to the magnet is directed:
(a) From N to S
(b) From S to N
(c) Vertically downwards
(d) Vertically upwards
Q4.
A current carrying conductor placed in magnetic field experiences a force. The displacement of the conductor in magnetic field can be increased by
(a) Decreasing the magnetic field.
(b) Decreasing the current in the conductor.
(c) Increasing the magnetic field
(d) None of the above
Q5.
A positively charged particle, say, an alpha particle projected towards west is deflected toward north by a magnetic field. The direction of the magnetic field is
(a) Upward
(b) downward
(c) towards south
(d) towards east
Q6.
When current is parallel to magnetic field, then force experience by the current carrying conductor placed in uniform magnetic field is
(a) Twice to that when angle is 60°
(b) Thrice to that when angle is 60°
(c) zero
(d) Infinite
Q7.
Which of the following factors affect the strength of force experience by a current carrying conduct in a uniform magnetic field?
(a) magnetic field strength
(b) magnitude of current in a conductor
(c) length of the conductor within magnetic field
(d) All of above.
Q8.
A magnetic field directed in north direction acts on an electron moving in east direction. The magnetic force on the electron will act
(a) vertically upwards
(b) towards east
(c) vertically downwards
(d) towards north
Q9.
According to Fleming’s left-hand rule, if the first finger points in the direction of X the second finger in the direction of Y then the thumb will point in the direction of Z .
(a) X – current; Y – field; Z – force
(b) X – field; Y – force; Z – current
(c) X – field; Y – current; Z – force
(d) X – current; Y – force; Z – field
Q10.
Observe the figure given below and answer the following questions:
(a) Write the special name given to the coil AB which has many circular turns of insulated copper wire.
(b) State the nature of magnetic field inside AB when a current is passed through it.
(c) Redraw the diagram and sketch the pattern of magnetic field lines through and around AB.
(d) List two factors on which the strength of the magnetic field produced by AB depends.
(e) How does the above coil behave like a bar magnet? Write any two similarities with a bar magnet.
(f) What is the effect of placing an iron core in the coil AB?
Q11.
What are magnetic field lines?
Q12.
Justify the following statements
(a) Two magnetic field lines never intersect each other.
(b) Magnetic field lines are closed curves.
Q13.
How is the strength of magnetic field near a straight current carrying conductor
(i) related to the strength of current in the conductor?
(ii) is affected by changing the direction of flow of current in the conductor?
Q14.
List three sources of magnetic fields.
Q15.
Identify the poles of the magnet in the given figure (1) and (2).
Q16.
How will the magnetic field produced at a point due to a current-carrying circular coil change if we:
(a) increase the current flowing through the coil?
(b) reverse direction of current through the coil?
(c) increase the number of turns in the coil?
Q17.
If the number of turns of a circular current carrying coil are doubled, then how will the magnetic field produced by it changes?
Q18.
State the rule to determine the direction of –
(a) magnetic field produced around a straight conductor carrying current,
(b) force experienced by a current-carrying straight conductor placed in a magnetic field which is perpendicular to it.
Q19.
(a) Under what condition is the force experienced by a current-carrying conductor placed in a magnetic field maximum?
(b) A proton beam is moving along the direction of a magnetic field. What force is acting on proton beam?
Q20.
Mention the factors on which the direction of force experienced by a current-carrying conductor placed in a magnetic field depend.
