cameroon gce advanced level 2025 fundamental and power electronics 1

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1. The frequency of the ac signal 75sin(100πt) is

A. 75Hz

B. 100Hz

C. 50Hz

D. 25Hz

2. If an ac signal of 1272​sin(100πt) is supplying a 2.2kW electric cooker and a 700W electric iron, connected in parallel, at the same time, what is the line current?

A. 22.8A

B. 17.32A

C. 5.5A

D. 16.12A

3. If the complex impedance of an R-L series circuit is 30+j30, calculate the circuit power factor.

A. 0.9

B. 0.6

C. 0.86

D. 0.51

4. In an AC circuit a low value of KVAR compared with KW indicates

A. Low efficiency

B. High power factor

C. Unity power factor

D. Maximum load current

5. The average power supplied to an inductor over one complete alternating current cycle is

A. IV2

B. VI2

C. IR2

D. 0

6. The power factor at resonance in R-L-C parallel circuit is

A. 0

B. Unity

C. 0.8

D. 0.98

7. In an ac circuit i(t)=100sin(100πt) and v(t)=100sin(100πt+3π​), the average power loss is

A. 100kW

B. 1.5kW

C. 2.5kW

D. 10kW

8. A voltage of 2mV at a frequency of 200kHz is applied to an RLC series circuit. If the current at resonance is 100μA, calculate the value of R.

A. 20Ω

B. 200Ω

C. 2Ω

D. 200K$\Omega$

9. What is the resonance frequency of the circuit in figure 1?

A. 5.24KHz

B. 4.22KHz

C. 1.13KHz

D. 6.65KHz

10. If the supply voltage to the circuit of figure 1 is 100Vac, what is the current at resonance?

A. 14A

B. 12A

C. 10A

D. 8A

11. What is the voltage across the inductor of the circuit in figure 1 at resonance?

A. 2168V

B. 4542V

C. 0V

D. 1756V

12. Calculate the value of the current I2​ in figure 2.

A. 10.90mA

B. 20.10mA

C. 9.10mA

D. 4.55mA