Extracted pages from 0625_s10_qp_31
Оценка 4.6

Extracted pages from 0625_s10_qp_31

Оценка 4.6
pdf
08.05.2020
Extracted pages from 0625_s10_qp_31
Extracted pages from 0625_s10_qp_31.pdf

8      (a) The transformer in Fig. 8.1 is used to convert 240 V a.c. to 6 V a.c.

primary           secondary coil coil

(480 turns)

Fig. 8.1

                  (i) Using the information above, calculate the number of turns on the secondary coil.

            number of turns =  ................................................ [2]                      (ii) Describe how the transformer works.

 ..................................................................................................................................

 ..................................................................................................................................

 ..................................................................................................................................

 ..................................................................................................................................

 ............................................................................................................................ [3]

                         (iii) State one way in which energy is lost from the transformer, and from which part it is lost.

 ............................................................................................................................ [1]

        (b) Fig. 8.2 shows a device labelled “IGCSE Transformer”.

Fig. 8.2

               Study the label on the case of the IGCSE Transformer.

(i)           What is the output of the device?  ....................................................................... [1]

(ii)          From the information on the case, deduce what other electrical component must be included within the case of the IGCSE Transformer, apart from a transformer.

 ............................................................................................................................ [1]

 (c) A transformer supplying electrical energy to a factory changes the 11 000 V a.c. supply to 440 V a.c. for use in the factory. The current in the secondary coil is 200 A.

                Calculate the current in the primary coil, assuming no losses from the transformer.

                                                                                      current =  ................................................ [2]

[Total: 10]

[Turn over

9 (a) Fig. 9.1 illustrates the left hand rule, which helps when describing the force on a currentcarrying conductor in a magnetic field.

thumb

motion / force

Fig. 9.1

                One direction has been labelled for you.

                In each of the other two boxes, write the name of the quantity that direction represents.

[1]

         (b) Fig. 9.2 shows a simple d.c. motor connected to a battery and a switch.

Fig. 9.2

(i)        On Fig. 9.2, write in each of the boxes the name of the part of the motor to which the arrow is pointing.             [2]

(ii)       State which way the coil of the motor will rotate when the switch is closed, when viewed from the position X.

 ............................................................................................................................ [1]

(iii)     State two things which could be done to increase the speed of rotation of the coil.

1. ...............................................................................................................................

2. ......................................................................................................................... [2][Total: 6]

[Turn over

The transformer in Fig. 8.1 is used to convert 240

The transformer in Fig. 8.1 is used to convert 240

Fig. 8.2 Study the label on the case of the

Fig. 8.2 Study the label on the case of the

Turn over 9 (a) Fig. 9.1 illustrates the left hand rule, which helps when describing the force on a currentcarrying conductor in a magnetic field

Turn over 9 (a) Fig. 9.1 illustrates the left hand rule, which helps when describing the force on a currentcarrying conductor in a magnetic field

Fig. 9.2 (i) On Fig

Fig. 9.2 (i) On Fig

[Turn over

[Turn over
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