MCQOPTIONS
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MCQOPTIONS
This section includes 657 Mcqs, each offering curated multiple-choice questions to sharpen your Testing Subject knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
What will be energy used by the battery if the battery has to drive 6.28 x 10¹⁸ electrons with potential difference of 20 V across the terminal ? |
| A. | 5 joules |
| B. | 10 joules |
| C. | 15 joules |
| D. | 20 joules |
| Answer» E. | |
| 2. |
All good conductors have high |
| A. | Conductance |
| B. | Resistance |
| C. | Reluctance |
| D. | Thermal conductivity |
| Answer» B. Resistance | |
| 3. |
The thickness of insulation provided on the conductor depends on |
| A. | The magnitude of voltage on the conductor |
| B. | The magnitude of current flowing through it |
| C. | Both (A) and (B) |
| D. | None of the above |
| Answer» B. The magnitude of current flowing through it | |
| 4. |
Conductance: mho :: |
| A. | Resistance : ohm |
| B. | Capacitance : Henry |
| C. | Inductance : farad |
| D. | lumen : steradian |
| Answer» B. Capacitance : Henry | |
| 5. |
Which of the following material has nearly zero temperature coefficient of resistance? |
| A. | Manganin |
| B. | Porcelain |
| C. | Carbon |
| D. | Copper |
| Answer» B. Porcelain | |
| 6. |
Which of the following materials has a negative temperature coefficient of resistance? |
| A. | Copper |
| B. | Aluminum |
| C. | Carbon |
| D. | Brass |
| Answer» D. Brass | |
| 7. |
You have to replace 1500 Q resistor in radio. You have no 1500 Q resistor but have several 1000 Q ones which you would connect |
| A. | Two in parallel |
| B. | Two in parallel and one in series |
| C. | Three in parallel |
| D. | Three in series |
| Answer» C. Three in parallel | |
| 8. |
When a voltage of one volt is applied, a circuit allows one micro ampere current to flow through it. The conductance of the circuit is |
| A. | 1 n-mho |
| B. | 106 mho |
| C. | 1 milli-mho |
| D. | None of the above |
| Answer» B. 106 mho | |
| 9. |
With rise in temperature the resistance of semiconductors |
| A. | Decreases |
| B. | Increases |
| C. | First increases and then decreases |
| D. | Remains constant |
| Answer» B. Increases | |
| 10. |
An electric filament bulb can be worked from |
| A. | D.C. supply only |
| B. | A.C. supply only |
| C. | Battery supply only |
| D. | All above |
| Answer» E. | |
| 11. |
Bulbs in street lighting are all connected in |
| A. | Parallel |
| B. | Series |
| C. | Series-parallel |
| D. | End-to-end |
| Answer» B. Series | |
| 12. |
Copper wire of certain length and resistance is drawn out to three times its length without change in volume, the new resistance of wire becomes |
| A. | 1/9 times |
| B. | 3 times |
| C. | 9 times |
| D. | Unchanged |
| Answer» D. Unchanged | |
| 13. |
All of the following are equivalent to watt except |
| A. | (Amperes) ohm |
| B. | Joules/sec. |
| C. | Amperes × volts |
| D. | Amperes/volt |
| Answer» E. | |
| 14. |
A thermistor has |
| A. | Positive temperature coefficient |
| B. | Negative temperature coefficient |
| C. | Zero temperature coefficient |
| D. | Variable temperature coefficient |
| Answer» D. Variable temperature coefficient | |
| 15. |
The S.I. unit of power is |
| A. | Henry |
| B. | Coulomb |
| C. | Watt |
| D. | Watt-hour |
| Answer» D. Watt-hour | |
| 16. |
Resistance of 220 V, 100 W lamp will be |
| A. | 4.84 Q |
| B. | 48.4 Q |
| C. | 484 ft |
| D. | 4840 Q |
| Answer» D. 4840 Q | |
| 17. |
Nichrome wire is an alloy of |
| A. | Lead and zinc |
| B. | Chromium and vanadium |
| C. | Nickel and chromium |
| D. | Copper and silver |
| Answer» D. Copper and silver | |
| 18. |
If the efficiency of a machine is to be high, what should be low? |
| A. | Input power |
| B. | Losses |
| C. | True component of power |
| D. | kWh consumed |
| Answer» C. True component of power | |
| 19. |
A resistance having rating 10 ohms, 10 W is likely to be a |
| A. | Metallic resistor |
| B. | Carbon resistor |
| C. | Wire wound resistor |
| D. | Variable resistor |
| Answer» D. Variable resistor | |
| 20. |
The resistance of a conductor varies inversely as |
| A. | Length |
| B. | Area of cross-section |
| C. | Temperature |
| D. | Resistivity |
| Answer» C. Temperature | |
| 21. |
In a series circuit with unequal resistances |
| A. | The highest resistance has the most of the current through it |
| B. | The lowest resistance has the highest voltage drop |
| C. | The lowest resistance has the highest current |
| D. | The highest resistance has the highest voltage drop |
| Answer» E. | |
| 22. |
Are the materials having electrical conductivity much less than most of the metals but much greater than that of typical insulators. |
| A. | Varistors |
| B. | Thermistor |
| C. | Semiconductors |
| D. | Variable resistors |
| Answer» D. Variable resistors | |
| 23. |
A rheostat differs from potentiometer in the respect that it |
| A. | Has lower wattage rating |
| B. | Has higher wattage rating |
| C. | Has large number of turns |
| D. | Offers large number of tapping |
| Answer» C. Has large number of turns | |
| 24. |
For testing appliances, the wattage of test lamp should be |
| A. | Very low |
| B. | Low |
| C. | High |
| D. | Any value |
| Answer» D. Any value | |
| 25. |
Two bulbs of 500 W and 200 W rated at 250 V will have resistance ratio as |
| A. | 4 : 25 |
| B. | 25 : 4 |
| C. | 2 : 5 |
| D. | 5 : 2 |
| Answer» D. 5 : 2 | |
| 26. |
Three 60 W bulbs are in parallel across the 60 V power line. If one bulb burns open |
| A. | There will be heavy current in the main line |
| B. | Rest of the two bulbs will not light |
| C. | All three bulbs will light |
| D. | The other two bulbs will light |
| Answer» E. | |
| 27. |
Which of the following materials has the least resistivity ? |
| A. | Zinc |
| B. | Lead |
| C. | Mercury |
| D. | Copper |
| Answer» E. | |
| 28. |
Temperature coefficient of resistance is expressed in terms of |
| A. | ohms/°C |
| B. | mhos/ohm°C |
| C. | ohms/ohm°C |
| D. | mhos/°C |
| Answer» D. mhos/°C | |
| 29. |
Varistors are |
| A. | Insulators |
| B. | Nonlinear resistors |
| C. | Carbon resistors |
| D. | Resistors with zero temperature coefficients |
| Answer» C. Carbon resistors | |
| 30. |
Whether circuit may be AC. or D.C. one, following is most effective in reducing the magnitude of the current. |
| A. | Reactor |
| B. | Capacitor |
| C. | Inductor |
| D. | Resistor |
| Answer» E. | |
| 31. |
The filament of an electric bulb is made of |
| A. | Carbon |
| B. | Aluminium |
| C. | Tungsten |
| D. | Nickel |
| Answer» D. Nickel | |
| 32. |
One Newton meter is same as |
| A. | One watt |
| B. | One joule |
| C. | Five joules |
| D. | One joule second |
| Answer» C. Five joules | |
| 33. |
Electric current passing through the circuit produces |
| A. | Magnetic effect |
| B. | Luminous effect |
| C. | Thermal effect |
| D. | Chemical effect |
| Answer» D. Chemical effect | |
| 34. |
Sparking occurs when a load is switched off because the circuit has high |
| A. | Resistance |
| B. | Inductance |
| C. | Capacitance |
| D. | Impedance |
| Answer» C. Capacitance | |
| 35. |
An open resistor, when checked with an ohmmeter reads |
| A. | Zero |
| B. | Infinite |
| C. | High but within tolerance |
| D. | Low but not zero |
| Answer» C. High but within tolerance | |
| 36. |
A 40 W bulb is connected in series with a room heater. If now 40 W bulb is replaced by 100 W bulb, the heater output will: |
| A. | Decrease |
| B. | Increase |
| C. | Remain same |
| D. | Heater will burn out |
| Answer» C. Remain same | |
| 37. |
A closed switch has a resistance of |
| A. | Zero |
| B. | About 50 ohms |
| C. | About 500 ohms |
| D. | Infinity |
| Answer» B. About 50 ohms | |
| 38. |
Two resistances Rl and Ri are connected in series across the voltage source where Rl > Ri. The largest drop will be across |
| A. | Rl |
| B. | Ri |
| C. | Either Rl or Ri |
| D. | None of them |
| Answer» B. Ri | |
| 39. |
It becomes more difficult to remove |
| A. | Any electron from the orbit |
| B. | First electron from the orbit |
| C. | Second electron from the orbit |
| D. | Third electron from the orbit |
| Answer» E. | |
| 40. |
An instrument which detects electric current is known as |
| A. | Voltmeter |
| B. | Rheostat |
| C. | Watt-meter |
| D. | Galvanometer |
| Answer» E. | |
| 41. |
Two lamps 100 W and 40 W are connected in series across 230 V (alternating). Which of the following statement is correct? |
| A. | 100 W lamp will glow brighter |
| B. | 40 W lamp will glow brighter |
| C. | Both lamps will glow equally bright |
| D. | 40 W lamp will fuse |
| Answer» C. Both lamps will glow equally bright | |
| 42. |
With rise in temperature the resistance of pure metals |
| A. | Increases |
| B. | Decreases |
| C. | First increases and then decreases |
| D. | Remains constant |
| Answer» B. Decreases | |
| 43. |
Voltage dependent resistors are used |
| A. | For inductive circuits |
| B. | To suppress surges |
| C. | As heating elements |
| D. | As current stabilizers |
| Answer» C. As heating elements | |
| 44. |
The hot resistance of the bulb's filament is higher than its cold resistance because the temperature coefficient of the filament is |
| A. | Zero |
| B. | Negative |
| C. | Positive |
| D. | About 2 ohms per degree |
| Answer» D. About 2 ohms per degree | |
| 45. |
The resistance of a parallel circuit consisting of two branches is 12 ohms. If the resistance of one branch is 18 ohms, what is the resistance of the other? |
| A. | 18 Q |
| B. | 36 Q |
| C. | 48 Q |
| D. | 64 Q |
| Answer» C. 48 Q | |
| 46. |
Electric pressure is also called |
| A. | Resistance |
| B. | Power |
| C. | Voltage |
| D. | Energy |
| Answer» D. Energy | |
| 47. |
A 3 Q resistor having 2 A current will dissipate the power of |
| A. | 2 watts |
| B. | 4 watts |
| C. | 6 watts |
| D. | 8 watts |
| Answer» D. 8 watts | |
| 48. |
In a lamp load when more than one lamp are switched on the total resistance of the load |
| A. | Increases |
| B. | Decreases |
| C. | Remains same |
| D. | None of the above |
| Answer» C. Remains same | |
| 49. |
In the case of direct current |
| A. | Magnitude and direction of current remains constant |
| B. | Magnitude and direction of current changes with time |
| C. | Magnitude of current changes with time |
| D. | Magnitude of current remains constant |
| Answer» B. Magnitude and direction of current changes with time | |
| 50. |
If a wire conductor of 0.2 ohm resistance is doubled in length, its resistance becomes |
| A. | 0.4 ohm |
| B. | 0.6 ohm |
| C. | 0.8 ohm |
| D. | 1.0 ohm |
| Answer» B. 0.6 ohm | |