Page 690 - SUBSEC October 2017_Neat

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16. A sinusoidal alternating current of a peak 18. A direct current of 5A dissipates heat
value 20A dissipates power of 50W in a in a given resistor at the same rate as a
resistor R. The value of the resistor is sinusoidal alternating current slowing
through the same resistor. What is the
(A) 0.03 Ω root mean square value of the alternating
(B) 0.06 Ω current?
(C) 0.13 Ω
(D) 0.25 Ω (A) 2 A

(B) 5A
17. Which of the following graphs BEST
represent the I -V characteristics of a silicon 5 2A
p - n unction diode? (C)

I/mA 5
(A) 0.5 A
(D) 2

V/V
0.7
19. The ratio of the secondary turns to the
primary turns in an ideal transformer is
1:30. A 120V a.c. supply is connected
I/mA to the primary coil and a load of 20 Ω
(B) 0.5 connected to the secondary coil. What is
the secondary current?

V/V
0.7 (A) 180 A
(B) 6 A
(C) 1.5 A
(D) 0.2 A
I/mA
(C) 0.5

V/V
0.7

I/mA
(D) 0.5

V/V
0.7

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02238010/SPEC 2017