JAMB and WAEC Physics questions

829 questions with answers and explanations. Tap an option to check yourself.

1. Question 381· Introductory electronics· JAMB

   In a p-type semiconductor, the majority charge carriers are

   • Aelectrons
   • Bholes
   • Cprotons
   • Dions

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   Explanation and discussion

2. Question 382· Introductory electronics· WAEC

   A semiconductor diode is mainly used as a

   • Arectifier
   • Bamplifier
   • Ccapacitor
   • Dtransformer

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   Explanation and discussion

3. Question 383· Introductory electronics· WAEC

   Adding a pentavalent impurity such as phosphorus to pure silicon produces

   • Aa p-type semiconductor
   • Ban n-type semiconductor
   • Can insulator
   • Da superconductor

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   Explanation and discussion

4. Question 384· Introductory electronics· JAMB

   Which of the following is a semiconductor?

   • Arubber
   • Bcopper
   • Csilicon
   • Dglass

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   Explanation and discussion

5. Question 385· Introductory electronics· JAMB

   The majority charge carriers in a p-type semiconductor are

   • Aelectrons
   • Bholes
   • Cprotons
   • Dneutrons

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   Explanation and discussion

6. Question 386· Introductory electronics· JAMB

   A diode is used in circuits because it

   • Ameasures current
   • Bstores charge
   • Cincreases voltage
   • Dallows current to flow in one direction only

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7. Question 387· Introductory electronics· JAMB

   A semiconductor doped with a pentavalent impurity such as phosphorus is

   • Aintrinsic
   • Bp-type
   • Cn-type
   • Dan insulator

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   Explanation and discussion

8. Question 388· Introductory electronics· JAMB

   Rectification is the process of

   • Aamplifying a signal
   • Bconverting d.c. to a.c.
   • Cconverting a.c. to d.c.
   • Dstoring charge

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9. Question 389· Introductory electronics· WAEC

   The output of an OR gate is 0 only when

   • Aall its inputs are 1
   • Ball its inputs are 0
   • Cany input is 1
   • Dthe inputs are different

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10. Question 390· Introductory electronics· JAMB

    A transistor can be used as

    • Aa battery
    • Ba rectifier only
    • Ca capacitor
    • Dan amplifier or a switch

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11. Question 391· Introductory electronics· JAMB

    A p-n junction diode conducts when:

    • Areverse biased
    • Bunbiased
    • Cforward biased
    • Dheated

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    Explanation and discussion

12. Question 392· Introductory electronics· WAEC

    A p–n junction diode is forward biased when the p-side is connected to the

    • Aearth only
    • Bnegative terminal of the battery
    • Cpositive terminal of the battery
    • Dcollector of a transistor

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13. Question 393· Introductory electronics· WAEC

    A semiconductor diode allows current to flow

    • Ain one direction only
    • Bin both directions equally
    • Conly with a.c.
    • Dnever

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14. Question 394· Introductory electronics· JAMB

    A diode connected with its n-side to the positive terminal of a battery

    • Abecomes a capacitor
    • Bconducts strongly
    • Cglows
    • Ddoes not conduct, because it is reverse biased

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15. Question 395· Introductory electronics· WAEC

    Silicon doped with boron becomes

    • Aa p-type semiconductor
    • Ban n-type semiconductor
    • Ca conductor
    • Dan insulator

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16. Question 396· Introductory electronics· WAEC

    A device that changes a.c. to d.c. is a

    • Arectifier
    • Btransformer
    • Camplifier
    • Dcapacitor only

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    Explanation and discussion

17. Question 397· Introductory electronics· WAEC

    A device that converts light energy directly into electrical energy is a

    • Asolar cell
    • Bdiode lamp
    • Ctransformer
    • Dthermocouple

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    Explanation and discussion

18. Question 398· Introductory electronics· WAEC

    The three terminals of a transistor are the

    • Aanode, cathode and grid
    • Bemitter, base and collector
    • Csource, gate and drain
    • Dpositive, negative and earth

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19. Question 399· Introductory electronics· JAMB

    A p-n junction diode is forward-biased when

    • Athe n-side is connected to the positive terminal
    • Bthe p-side is connected to the positive terminal
    • Cno voltage is applied
    • Dit is heated

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20. Question 400· Light: reflection· JAMB

    An object is placed 15 cm from a concave mirror of focal length 10 cm. Find the image distance.

    • A30 cm
    • B6 cm
    • C25 cm
    • D5 cm

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    Explanation and discussion