Page 98 - Physics_Form_2

Physics for Secondary Schools

of conducting wire. Should you Circuit Glow/ Explanation
let him? Why or why not? Not Glow
10. A wire of length 28 cm and
radius 0.75 mm is wound around
a cylindrical tube to form a
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solenoid. If the resistivity of the
wire is 5.6×10 Ω m, Calculate its
-8
resistance.

11. Three identical resistors each with
a resistance of 10 Ω are connected
in series to a 12 V battery with an
internal resistance of 2 Ω:
(a) What is the total resistance of 13. The diagram in Figure 2.71 shows
the circuit? an electric circuit containing three
(a) How much power is supplied resistors.
by the battery? R
1 A
(b) How much power is dissipated
in each of the external resistors?
(c) How much power is dissipated V 1 R 2 R 3
by the battery’s internal
resistance?
12. Look at the circuits below. If the B
bulb(s) will glow, place a tick next Figure 2.71
to the picture and explain why it will Given that, the battery has a
glow. If the bulb(s) will not glow, voltage of 24 V and a negligible
place a cross next to the picture and internal resistance and that
explain why it will not glow. R  1 5 , R 2  10  , R  3 10 

Circuit Glow/ Explanation determine:
Not Glow (a) the total resistance in the circuit.
(b) the current that flows through
R 1 .
(c) the current that flows through
R 2 .
(d) how much current flows through
R 3 .
(e) the potential difference between
points A and B.

92
Student’s Book Form One

Physics Form 2 Final.indd 92 25/10/2025 10:26