MCQOPTIONS
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MCQOPTIONS
This section includes 869 Mcqs, each offering curated multiple-choice questions to sharpen your BITSAT knowledge and support exam preparation. Choose a topic below to get started.
| 651. |
For a P-N diode, the number of minority carriers crossing the junction depends on |
| A. | forward bias voltage |
| B. | potential barrier |
| C. | rate of thermal generation of electron hole pairs |
| D. | none of the above |
| Answer» D. none of the above | |
| 652. |
Assertion (A): A JFET can be used as a current source.Reason (R): In beyond pinch off region the current in JFET is nearly constant. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not a correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are true but R is not a correct explanation of A | |
| 653. |
Permalloy is |
| A. | a variety of stainless steel |
| B. | a polymer |
| C. | a conon-ferrous alloy used in aircraft industry |
| D. | a nickel an iron alloy having high permeability |
| Answer» E. | |
| 654. |
A 2 bit binary multiplier can be implemented using |
| A. | 2 I/P only |
| B. | 2 I/P XORs and 4 I/P and gates only |
| C. | two 2 I/Ps NOR and one XNOR gate |
| D. | XOR gates and shift Register |
| Answer» C. two 2 I/Ps NOR and one XNOR gate | |
| 655. |
If the drift velocity of holes under a field gradient of 100 V/m is 5m/sec. Their mobility is |
| A. | 0.05 |
| B. | 0.5 |
| C. | 50 |
| D. | 500 |
| Answer» B. 0.5 | |
| 656. |
Which of the following diode is designed to operate in the breakdown region? |
| A. | Signal diode |
| B. | Power diode |
| C. | Zener diode |
| D. | None of the above |
| Answer» D. None of the above | |
| 657. |
The first and the last critical frequency of an RC driving point impedance function must respectively by |
| A. | a zero and a pole |
| B. | a zero and a zero |
| C. | a pole and a pole |
| D. | a pole and a zero |
| Answer» B. a zero and a zero | |
| 658. |
For a full wave bridge rectifier supplied with 50 Hz a.c., the lowest ripple frequency will be |
| A. | 50 Hz |
| B. | 100 Hz |
| C. | 200 Hz |
| D. | 400 Hz |
| Answer» C. 200 Hz | |
| 659. |
When a high voltage reference is required it is advantageous to use two or more zener diodes in series to allow |
| A. | higher voltage |
| B. | higher dissipation |
| C. | lower temperature coefficient |
| D. | all of the above |
| Answer» E. | |
| 660. |
The conductivity of an intrinsic semiconductor is (symbols have the usual meanings). |
| A. | generally less than that a doped semiconductor |
| B. | σi = eni (μn - μp) |
| C. | σi = eni (μn + μp) |
| D. | σi = ni (μn - μp) |
| Answer» D. σi = ni (μn - μp) | |
| 661. |
Covalent bond energy in Germanium is approximately |
| A. | 3.8 eV |
| B. | 4.7 eV |
| C. | 7.4 eV |
| D. | 12.5 eV |
| Answer» D. 12.5 eV | |
| 662. |
Ferrities are particularly suited for high frequency applications because of their |
| A. | low distortion |
| B. | low eddy current loss |
| C. | high conductivity |
| D. | high mobility |
| Answer» C. high conductivity | |
| 663. |
The ac resistance of a forward biased p-n junction diode operating at a bias voltage V and carrying current 'I' is |
| A. | 0 |
| B. | constant value independent of V and I |
| C. | V/I |
| D. | ΔV/ΔI |
| Answer» D. ΔV/ΔI | |
| 664. |
As temperature increases the number of free electrons and holes in an intrinsic semiconductor |
| A. | increases |
| B. | decreases |
| C. | remains the same |
| D. | may increase or decrease |
| Answer» B. decreases | |
| 665. |
Hall coefficient is reciprocal of charge density. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» B. False | |
| 666. |
A power supply has full-load voltage of 20 V. What will be its no load voltage when its voltage regulation is 100% |
| A. | 0 V |
| B. | 10 V |
| C. | 20 V |
| D. | 40 V |
| Answer» E. | |
| 667. |
Which materials find application in MASER? |
| A. | Diamagnetic |
| B. | Paramagnetic |
| C. | Ferromagnetic |
| D. | Ferrimagnetic |
| Answer» B. Paramagnetic | |
| 668. |
Consider the following statements about conditions that make a metal semiconductor contact rectifying 1. N type semiconductor with work function φs more than work function φM of metal2. N type semiconductor with work function φs less than work function φM of metal3. P type semiconductor with work function φs more than work function φM of metal4. P type semiconductor with work function φs less than work function φM of metalOf these statements |
| A. | 1 and 3 are correct |
| B. | 2 and 3 are correct |
| C. | 1 and 4 are correct |
| D. | 2 and 4 are correct |
| Answer» B. 2 and 3 are correct | |
| 669. |
In n type MOSFET, the substrate |
| A. | is p type |
| B. | is n type |
| C. | is metallic |
| D. | may be p or n type |
| Answer» B. is n type | |
| 670. |
When p-n junction is reverse biased the holes in p material move towards the junction and electrons in n material move away from the junction. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» C. May be True or False | |
| 671. |
Which impurity atom will give p type semiconductor when added to intrinsic semiconductor? |
| A. | Phosphorus |
| B. | Boron |
| C. | Arsenic |
| D. | Antimony |
| Answer» C. Arsenic | |
| 672. |
A diode is operating in forward region and the forward voltage and current are v = 3 + 0.3 sin ωt (volts) and i = 5 + 0.2 sin ωt (mA). The average power dissipated is |
| A. | 15 mW |
| B. | about 15 mW |
| C. | 1.5 mW |
| D. | about 1.5 mW |
| Answer» C. 1.5 mW | |
| 673. |
Spot the odd one out |
| A. | aluminium |
| B. | silver |
| C. | porcelain |
| D. | copper |
| Answer» D. copper | |
| 674. |
In an ideal diode there is no breakdown, no __________ current, and no forward __________ drop. |
| A. | reverse, voltage |
| B. | forward, current |
| C. | forward, voltage |
| D. | reverse, current |
| Answer» B. forward, current | |
| 675. |
The normal operation of JFET is |
| A. | constant voltage region |
| B. | constant current region |
| C. | both constant voltage and constant current regions |
| D. | either constant voltage or constant current region |
| Answer» C. both constant voltage and constant current regions | |
| 676. |
It is required to trace the output characteristics of a CE bipolar transistor on a CRO screen. The proper method is |
| A. | apply the voltage drop across collector resistance to Y input, disconnect sweep generator and apply VCE to X input |
| B. | apply voltage drop across collector resistance to Y input |
| C. | apply VCE to X input |
| D. | apply VCE to Y input, disconnect the sweep generator and apply voltage drop across collector resistance to X input |
| Answer» B. apply voltage drop across collector resistance to Y input | |
| 677. |
Due to the formation of Schottky defects the density of the crystal |
| A. | increases slightly |
| B. | increases appreciably |
| C. | decreases slightly |
| D. | decreases appreciably |
| Answer» D. decreases appreciably | |
| 678. |
The threshold voltage of an n-channel enhancement mode MOSFET is 0.5 when the device is biased at a gate voltage of 3V. Pinch off would occur at a drain voltage of |
| A. | 1.5 V |
| B. | 2.5 V |
| C. | 3.5 V |
| D. | 4.5 V |
| Answer» C. 3.5 V | |
| 679. |
In a triode the potential of grid (with respect to cathode) is usually |
| A. | zero |
| B. | negative |
| C. | positive |
| D. | zero or positive |
| Answer» C. positive | |
| 680. |
The concentration of minority carriers in an extrinsic semiconductor under equilibrium is |
| A. | directly proportional to the doping concentration |
| B. | inversely proportional to doping concentration |
| C. | directly proportional to intrinsic concentration |
| D. | inversely proportional to the intrinsic concentration |
| Answer» C. directly proportional to intrinsic concentration | |
| 681. |
Calculate the resistivity of n-type semiconductor from the following data, Density of holes = 5 x 1012 cm-3. Density of electrons = 8 x 1013 cm-3, mobility of conduction electron = 2.3 x 104 cm²/ V-sec and mobility of holes = 100 cm²/V-sec. |
| A. | 0.43 Ω-m |
| B. | 0.34 Ω-m |
| C. | 0.42 Ω-m |
| D. | 0.24 Ω-m |
| Answer» C. 0.42 Ω-m | |
| 682. |
The emission of light is LED due to |
| A. | emission of holes |
| B. | emission of electrons |
| C. | generation of electromagnetic radiations |
| D. | conversion of heat energy into illumination |
| Answer» D. conversion of heat energy into illumination | |
| 683. |
The sensitivity of human eyes is maximum at |
| A. | white portion of spectrum |
| B. | green portion of spectrum |
| C. | red portion of spectrum |
| D. | violet portion of spectrum |
| Answer» C. red portion of spectrum | |
| 684. |
For a junction FET in the pinch off region as the drain voltage is increased, the drain current |
| A. | becomes zero |
| B. | abruptly decreases |
| C. | abruptly increases |
| D. | remains constant |
| Answer» E. | |
| 685. |
The output, V-I characteristics of an Enhancement type MOSFET has |
| A. | only an ohmic region |
| B. | only a saturation region |
| C. | an ohmic region at low voltage value followed by a saturation region at higher voltages |
| D. | an ohmic region at large voltage values preceded by a saturation region at lower voltages |
| Answer» D. an ohmic region at large voltage values preceded by a saturation region at lower voltages | |
| 686. |
An electrically neutral semiconductor has |
| A. | no free charges |
| B. | no majority carriers |
| C. | no minority carriers |
| D. | equal number of positive and negative charges |
| Answer» E. | |
| 687. |
When a ferromagnetic substance is magnetised, small changes in dimensions occur. Such a phenomenon is known as |
| A. | magnetic hystresis |
| B. | magnetic expansion |
| C. | magneto striction |
| D. | magneto calorisation |
| Answer» D. magneto calorisation | |
| 688. |
Human body cannot sustain electric current beyond |
| A. | 1 μA |
| B. | 10 μA |
| C. | 5 μA |
| D. | 35 μA |
| Answer» E. | |
| 689. |
In a JFET, the drain current is maximum when |
| A. | VGS = VDS |
| B. | VGS = pinch off voltage |
| C. | VGS = 0 |
| D. | VGS is negative |
| Answer» D. VGS is negative | |
| 690. |
The Hall constant in Si bar is given by 5 x 103 cm³/ coulomb, the hole concentration in the bar is given by |
| A. | 105/cm³ |
| B. | 1.25 x 1015/cm³ |
| C. | 1.5 x 1015/cm³ |
| D. | 1.6 x 1015/cm³ |
| Answer» C. 1.5 x 1015/cm³ | |
| 691. |
The voltage across the secondary of the transformer in a half wave rectifier with a shunt capacitor filter is 50 volts. The maximum voltage that will occur on the reverse biased diode will be |
| A. | 100 V |
| B. | 88 V |
| C. | 50 V |
| D. | 25 V |
| Answer» B. 88 V | |
| 692. |
As the reverse voltage is increased, the depletion layer |
| A. | becomes narrow |
| B. | widens |
| C. | remains the same |
| D. | reduce to zero |
| Answer» C. remains the same | |
| 693. |
In CE connection, the leakage current of a transistor is about |
| A. | 10 x 10¯⁹ A |
| B. | 5 x 10¯⁶ A |
| C. | 200 x 10¯⁶ A |
| D. | 5 x 10¯³ A |
| Answer» D. 5 x 10¯³ A | |
| 694. |
In a JFET the width of channel is controlled by |
| A. | gate voltage |
| B. | drain current |
| C. | source current |
| D. | all of the above |
| Answer» B. drain current | |
| 695. |
Assertion (A): A p-n junction has high resistance in reverse direction.Reason (R): When a reverse bias is applied to p-n junction, the width of depletion layer increases. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not a correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are true but R is not a correct explanation of A | |
| 696. |
In a JFET |
| A. | drain current is very nearly equal to source current |
| B. | drain current is much less than source current |
| C. | drain current may be equal to or less than source current |
| D. | drain current may be even more than source current |
| Answer» B. drain current is much less than source current | |
| 697. |
The maximum power handling capacity of a resistor depends on |
| A. | total surface area |
| B. | resistance value |
| C. | thermal capacity of the resistor |
| D. | resistivity of the material used in the resistor |
| Answer» D. resistivity of the material used in the resistor | |
| 698. |
Generally, the gain of a transistor amplifier falls at high frequency due to the |
| A. | internal capacitance of the device |
| B. | coupling capacitor at the I/P |
| C. | skin effect |
| D. | coupling capacitor at the O/P |
| Answer» B. coupling capacitor at the I/P | |
| 699. |
The diameter of an atom is |
| A. | 10¯⁶ metre |
| B. | 10¯¹ᴼ metre |
| C. | 10¯¹⁵ metre |
| D. | 10¯²¹ metre |
| Answer» C. 10¯¹⁵ metre | |
| 700. |
In a solar cell, the photovoltaic voltages is the voltage at which the resultant current is |
| A. | positive |
| B. | zero |
| C. | negative |
| D. | rated current |
| Answer» C. negative | |