The figure below shows two parallel magnets with unlike poles adjacent to each other. Sketch the magnetic field pattern around the magnets (2mks)
Solution
1 Comment
State the conditions for generation of e.m.f from a magnet (2mks)
K.C.S.E Physics Q & A - MODEL 2019PP2QN18
(ii) Describe how a magnet can be demagnetised using the electrical method.
(b) You are provided with two iron bars P and Q. One of the bars is magnetized while the other is not. Explain how themagnetized bar can be identified without using a magnet or magnetic material. (c)Figure 12 shows two identical copper coils X and Y placed close to each other. Coil X is connected to a DC power supply while coil Y is connected to a galvanometer. 
Explain what is observed on the galvanometer When the Switch is closed.
(ii) State What is observed on the galvanometer when the switch is opened. (iii) State what wou1d be observed if the number of turns in coil Y is doubled.
answers
(a) Place the bar magnet inside a solenoid placed in the an East-West direction then pass an alternating current through the solenoid
(b) Suspend each of the bars through its center of gravity and set it swinging in a horizontal plane shows a vertical axis through its centre The magnetized bar will always come to rest in a north-south direction (c) (i) The galvanometer pointer first deflects then moves back when the switch is closed a current builds up in a coil X and due to change influx linkage an emf is induced in coil Y making an induced current to flow through the galvanometer during the time current in coil X is rising. When current through coil X is steady no induced current flows through the galvanometer since there is no change in flux linkage Therefore pointer deflects back (ii) Pointer deflects in the opposite direction. (iii) Magnitude of deflection increases K.C.S.E Physics Q & A - MODEL 2019PP2QN04
Figure 2 shows an incomplete circuit for an electromagnet.
(a) Complete the diagram to show how a battery should be connected at A so that the polarities at P and Q are South and North respectively.
(b) State two ways in which the strength of the electromagnet in (a) can be increased.
answers
(b) Increasing the number of turns in the coil
Increasing the current (or number of cells)
K.C.S.E Physics Q & A - MODEL 2019PP2QN03
State two properties of magnetic field lines around a bar magnet.
answers
K.C.S.E Physics Q & A - MODEL 2018PP2QN03
Figure 1 shows a bar magnet AB suspended by a string.
When the North pole of another magnet is brought close to end A, there is repulsion State the polarity of end B.
answer
K.C.S.E Physics Q & A - MODEL 2018PP2QN02
State one characteristic of soft X-rays that distinguish them from hard X-rays.
answer
K.C.S.E Physics Q & A - MODEL 2017PP2QN06
Figure 1 shows an insulated wire wound on a U-shaped iron core connected to a battery.
Determine the polarity of A.
answer
K.C.S.E Physics Q & A - MODEL 2017PP2QN02
In a laboratory there are four metals — tin, nickel, copper and cobalt. Of these metals, name the metals that are;
(a) magnetic. (b) non-magnetic.
answers
K.C.S.E Physics Q & A - MODEL 2016PP2QN02
.An un-magnetized steel rod is clamped facing North-South direction and then hammered repeatedly for some time. When tested, it is found to be magnetized. Explain this observation.
answer
K.C.S.E Physics Q & A - MODEL 2015PP2QN06
State two ways in which the strength of an electromagnet can be increased.
answer
K.C.S.E Physics Q & A - MODEL 2015PP2QN04
Figure 2 shows a soft iron bar AB placed in a coil near a freely suspended magnet.
Explain the observation made when the switch is closed.
answer
K.C.S.E Physics Q & A - MODEL 2014PP2QN07
Figure 4 shows the magnetic field pattern around two bar magnets placed side by side.
Indicate on the diagram the poles of each magnet.
answer
K.C.S.E Physics Q & A - MODEL 2014PP2QN05
Figure 3 shows a nail on which a wire is to be wound to make an electromagnet.
By drawing, show how the wire should be wound around the nail so that end A becomes a north pole and end B a south pole.
answer
K.C.S.E Physics Q & A - MODEL 2013PP2QN019
(a) Figure 14 shows an E shaped steel block being magnetized by a current through two coils in series.
On the figure, indicate
(i) the north and south poles of the resulting magnet (ii) the complete magnetic field pattern between the poles. (b) Figure 15 shows the permanent magnet made in part (a) above. 
A coil wound loosely on the middle limb is connected in series with a low voltage a.c. and a switch. State and explain the observation made on the coil when the switch is closed.
(c) In a simple cell, the zinc plate gets negatively charged and the copper plate gets positively charged. (i) Name the electrolyte in the cell. (ii) Explain how: (I) Zinc gets negatively charged. (II) Copper gets positively charged (iii) State what constitutes the current when a wire is used to connect the zinc plate and the copper plate externally.
answers
(b) coil moves to and fro
force on coil varies direction as current varies indirection. (c) (i) dilute sulphuric acid (ii) (I) Zinc ions go into acid leaving electrons on the plate (Il) Give up electrons to discharge hydrogen Ions. (iii) Electrons flow from zinc plate to the copper plate.
K.C.S.E Physics Q & A - MODEL 2013PP2QN03
State the reason why the magnetic field strength of a magnet is greatest at the poles.
answer
K.C.S.E Physics Q & A - MODEL 2012PP2QN11
Figure 10, shows the cross section of a conductor held between two magnets and carrying a current out of the paper.
Indicate with an arrow on the diagram the direction in which the conductor will move when it is released.
answer
K.C.S.E Physics Q & A - MODEL 2011PP2QN06
One method of producing a weak magnet is to hold a steel rod in the North South direction and then hammer it continuously for some time. Using the domain theory of magnetism explain how this method works.
ANSWER
K.C.S.E Physics Q & A - MODEL 2010PP2QN03
Figure 3, shows a diagram of a current-carrying wire wound on a U-shaped soft iron.
Draw the magnetic field pattern around P and Q.
answer
K.C.S.E Physics Q & A - MODEL 2010PP2QN02
Figure 2(a), shows a magnetic compass placed under a horizontal wire XV
A large current is passed from X to Y. Draw the final position of the magnetic compass needle in figure 2b.
answer
K.C.S.E Physics Q & A - MODEL 2009PP2QN10
Figure 5 shows a magnet being moved towards a stationary solenoid. It is observed that a current flows through the circuit in a direction Q to P.
Explain:
(i) How the current is produced (ii) Why the current flows from Q to P
answer
(i) Movement of magnet causes flux linkage to change
E.M.F is produced in the cell. (ii) When 1 flow from Q to P, a N. pole is created which opposes the approaching pole (long’s law).
K.C.S.E Physics Q & A - MODEL 2009PP2QN05
An electromagnet is made by winding insulated copper wire on an iron core. State two changes that could be made to increase the strength of the electromagnet.
answer
K.C.S.E Physics Q & A - MODEL 2008PP2QN06
Figure 3 shows a flat spring made of iron clamped horizontally on the bench over a solenoid
When the switch is closed, the spring vibrates. Explain this observation.
answer
K.C.S.E Physics Q & A - MODEL 2008PP2QN04
An un-magnetized steel rod is clamped facing North-South direction and then hammered repeatedly for some time. When tested, it is found to be magnetized. Explain this observation
answer
K.C.S.E Physics Q & A - MODEL 2007PP2QN03
Figure 2 shows a horse – shoe magnet whose poles are labeled and two other magnets near it.
Iron are attracted to the lower ends of the n\magnets as shown. 
Identify the poles marked X and Y
X Y
ANSWER
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