CBSE Questions for Class 12 Medical Physics Semiconductor Electronics: Materials, Devices And Simple Circuits Quiz 14 - MCQExams.com


1820919_0ecd54870db64c88b9e96b6e01920b45.png
  • Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
  • Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
  • Assertion is correct but Reason is incorrect
  • Both Assertion and Reason are incorrect
Which is the wrong statement in following sentences? A device in which $$P$$ and $$N-$$ type semiconductors are used is more useful then a vacuum type because 
  • Power is not necessary to heat filament
  • It is more stable
  • Very less heat is produced in it
  • Its efficiency is high due to a high voltage across the junction
The output of a $$NAND$$ gate is $$0$$
  • If both input are $$0$$
  • If one input is $$0$$ and the other input is $$1$$
  • If both input are $$1$$
  • Either if both inputs are $$1$$ or if one of the input is $$1$$ and the other $$0$$
The value of plate current in the given circuit diagram will be
1820908_536726c1b5554713a013e70b3370fbda.png
  • $$3\ mA$$
  • $$8\ mA$$
  • $$13\ mA$$
  • $$18\ mA$$
GaAs is
  • Element semiconductor
  • Alloy semiconductor
  • Bad conductor
  • Metallic semiconductor
When a potential difference is applied across, the current passing through
  • An insulator at $$0K$$ is zero
  • A semiconductor at $$0K$$ is zero
  • A metal at $$0K$$ is zero
  • A $$P-N$$ diode at $$300K$$ is finite, if it reverse biased
Zener diode is used as 
  • Half wave rectifier
  • Full wave rectifier
  • $$ac$$ voltage stabilizer
  • $$dc$$ voltage stabilizer
Which gates is represented by this figure
1820887_260a8611c4824b4da6ffe8f211500235.png
  • $$NAND$$ gate
  • $$AND$$ gate
  • $$NOT$$ gate
  • $$OR$$ gate

1820878_9971713d99da4d9babebe5bfd9efb1c6.png
  • Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
  • Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
  • Assertion is correct but Reason is incorrect
  • Both Assertion and Reason are incorrect
Select the correct statements from the following
  • A diode can be used as a rectifier
  • A diode can not be used as a rectifier
  • The current in a diode always proportional to the applied voltage
  • The linear portion of the $$I-V$$ characteristics of a triode is used for amplification without distortion
Current in the circuit will bw
1821095_3fcac88a30e44424b97c197f9a979c55.png
  • $$\dfrac {5}{40}A$$
  • $$\dfrac {5}{50}A$$
  • $$\dfrac {5}{10}A$$
  • $$\dfrac {5}{20}A$$
At room temperature, a $$P-$$ type semiconductor has
  • Large number of holes and few electrons
  • Large number of free electrons and few holes
  • Equal number of free electrons and holes
  • No electrons or holes
The grid in a triode value is used
  • To increases the thermionic emission
  • To control the plate to cathode current
  • To reduce the inter-electrode capacity
  • To keep cathode at constant potential

1820931_250bcd0164414199aac929be6ce38a47.png
  • Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
  • Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
  • Assertion is correct but Reason is incorrect
  • Both Assertion and Reason are incorrect
In the following circuit find $$l_1$$ and $$l_2$$ 
1821114_03e22c009ee94a7e9a6884ed7ca7add7.png
  • $$0,0$$
  • $$5\ mA, 5\ mA$$
  • $$5\ mA, 0$$
  • $$0.5\ mA$$
The following transistor circuit is equivalent to which logic gate ?
1290963_4b6d85b9dc3d45eb8de487b79fbb9a8e.PNG
  • OR
  • NAND
  • XOR
  • AND
The following configuration of gate is equivalent to
1821124_110248e5777a43a0864386294f2bc104.png
  • $$NAND$$
  • $$XOR$$
  • $$OR$$
  • $$None\ of\ these$$
Doid is used as a/an
  • Oscillator
  • Amplifier
  • Rectifier
  • Modulator
The charge on a hole is equal to the charge of
  • Zero
  • Proton
  • Neutron
  • Electron
Series resistance is connected in the Zener diode circuit to
  • properly reverse bias the Zener
  • protect the Zener
  • properly forward bias the Zener
  • protect the load resistance
Electric current is due to drift of electron in
  • Metallic conductor
  • Semi-conductor
  • Both $$(a)$$ and $$(b)$$
  • None of these
A metallic surface with work function of $$2\ eV$$, on heating to a temperature of $$800\ K$$ gives an emission current of $$1\ mA$$. If another metallic surface having the same surface area, same emission constant but function $$4\ eV$$ is heated to a temperature of $$1600\ K$$ then the emission current will be
  • $$1\ mA$$
  • $$2\ mA$$
  • $$4\ mA$$
  • $$None\ of\ these$$
A logic gate is an electronic circuit which
  • makes logical decisions.
  • allows electron flow only in one direction.
  • works using binary algebra.
  • alternates between $$0$$ and $$1$$ value.
The given figure shows the wave forms for two inputs $$A$$ and $$B$$ and that for the output $$Y$$ of a logic circuit. The logic circuit is 
1821193_97344621bf874527be1dc116ab88d89b.png
  • An $$AND$$ gate
  • An $$OR$$ gate
  • An $$NAND$$ gate
  • An $$NOT$$ gate
The symbol shown in the adjoining figure is
1843941_ea229274311447d7864929d226d13e2e.PNG
  • NOT gate
  • OR gate
  • AND gate
  • NOR gate
The following figure shows a logic gate circuit with two inputs A and B the output Y. The voltage waveforms of A, B and Y are as given-
The logic gate is-








68946.jpg
  • OR gate
  • AND gate
  • NAND gate
  • NOR gate
A truth table is given below. Which of the following has this type of truth table ?
A
0
1
0
1
B
0
0
1
1
Y
1
0
0
0
  • XOR gate
  • NOR gate
  • AND gate
  • OR gate
A piece of copper and another of germanium are cooled from room temperature to 80 K. The resistance of:
  • each of them increases
  • each of them decreases
  • copper increases and germanium decreases
  • copper decreases and germanium increases.
A Zener diode is connected to a battery and a load as shown. The currents $$I$$, $$I_Z$$ and $$I_L$$ are respectively
99259.jpg
  • $$12.5 mA, 5 mA, 7.5 mA$$
  • $$15 mA, 7.5 mA, 7.5 mA$$
  • $$15 mA, 7.5 mA, 5 mA$$
  • $$12.5 mA, 7.5 mA, 5 mA$$
Which logic gate is represented by the following combination of logic gates:
76935.png
  • OR
  • NAND
  • AND
  • NOR
In the circuit shown in figure, the base current $$I_{B}$$ is $$10 \mu A$$ and the collector current is $$5.2 mA$$. The value of $$V_{BE}$$ is

77195.jpg
  • $$0.1 V$$
  • $$0.3 V$$
  • $$0.5 V$$
  • None of these
In the circuit shown, the diodes are ideal. $$A_1$$ and $$A_2$$ are ammeters of resistance $$5\Omega$$ each. The potentials of the points A, B, C and D are $$V_A, V_B, V_C$$ and $$V_D$$ respectively. $$|V_A-V_B|=10V$$

151998.png
  • $$A_1$$ and $$A_2$$ will always show the same reading
  • the readings of $$A_1$$ and $$A_2$$ will depend on whether $$V_A > V_B$$ or $$V_A < V_B$$
  • the readings of either of $$A_1$$ or $$A_2$$ or both will be $$1 A$$ in all cases
  • If $$V_A > V_B, A_1$$ will show no deflection
A semiconductor X is made by doping a germanium crystal with arsenic $$(Z=33)$$. A second semiconductor Y is made by doping germanium with indium$$(Z=49)$$. The two are joined end to end and connected to a battery as shown. Which of the following statements is correct?
1100743_f90489a23d704ad0bad662e45f40b088.png
  • X is P-type, Y is N-type and the junction is forward biased
  • X is N-type, Y is P-type and the junction is forward biased
  • X is P-type, Y is N-type and the junction is reverse biased
  • X is N-type, Y is P-type and the junction is reverse biased
The real time variation of input signals A and B are as shown below. If the inputs are fed into NAND gate, then select the output signal from the following
211270.jpg
For both pure and doped silicon, calculate the probability that a state at the bottom of the silicon conduction band is occupied?
211316_25c5cae587714f579924e793731baa78.png
  • 5.20 $$\times$$ 10$$^{-2}$$
  • 1.40 $$\times$$ 10$$^{-2}$$
  • 10.5 $$\times$$ 10$$^{-2}$$
  • 14 $$\times$$ 10$$^{-2}$$
Calculate the probability that a donor state in the doped material is occupied?
211317_4c6a0b993f22422483a9f90f953ceaeb.png
  • 0.824
  • 0.08
  • 0.008
  • 8.2
The following circut represents
211206_997493f2f44f4a21bcc9cac0c58f842a.png
  • OR gate
  • XOR gate
  • AND gate
  • NAND gate
The power output of the laser must be
  • $$5.5 W$$
  • $$11 W$$
  • $$16.5 W$$
  • $$22 W$$
A small mirror of mass m is suspended by a light thread of length $$l$$. A short pulse of laser falls on the mirror with energy $$E$$. Then, which of the following statement is correct?

163798.png
  • If the pulse falls normally on the mirror, it deflects by $$\theta=2E/(mc\sqrt {2gl})$$
  • If the pulse falls normally on the mirror, it deflects by $$\theta=2E/(mc\sqrt {2g})$$
  • Impulse in thread depends on angle at which the pulse falls on the mirror
  • None of the above
The following configuration of gate is equivalent to
211219.jpg
  • NAND gate
  • XOR gate
  • OR gate
  • NOR gate
The diagram of a logic circuit is given below. The output $$F$$ of the circuit is represented by
211207.jpg
  • $$W. (X +Y)$$
  • $$W. (X .Y)$$
  • $$W + (X.Y)$$
  • $$W + (X +Y)$$
Find the minimum load resistance which can be used for the zener diode as shown in figure. Given, $$V_Z=10 V, R_Z=0 \Omega,  R=450 \Omega, I_Z(min)=2 mA $$ and $$I_Z(max)=60 mA$$
507026.png
  • $$0 \Omega$$
  • $$333.3 \Omega$$
  • $$31.95 \Omega$$
  • $$319.5 \Omega$$
The value of the resistor, $$R_S$$, needed in the DC voltage regulator circuit shown here, equals

309961.png
  • $$\dfrac{(V_i+V_L)}{(n+1)I_L}$$
  • $$\dfrac{(V_i-V_L)}{n I_L}$$
  • $$\dfrac{(V_i+V_L)}{n I_L}$$
  • $$\dfrac{(V_i-V_L)}{(n+1)I_L}$$
The maximum efficiency of a full wave rectifier is 
  • $$\dfrac{4}{\pi^{2}}\times100\%$$
  • $$\dfrac{8}{\pi^{2}}\times100\%$$
  • $$40\%$$
  • $$80\%$$
A zener diode is specified as having a breakdown voltage of $$9.1 V$$, with a maximum power dissipation of $$364 \ mW$$. What is the maximum current the diode can handle? 
  • $$40 \ mA$$
  • $$60 \ mA$$
  • $$50 \ mA$$
  • $$45 \ mA$$
A NOR gate and a NAND gate are connected as shown in the figure. Two different sets of inputs are given to this setup. In the first case, the inputs to the gates are $$A=0,B=0,C=0$$. In the second case, the inputs are $$A=1,B=0,C=1$$. The output $$D$$ in the first case and second case respectively are:
470375.PNG
  • $$0$$ and $$0$$
  • $$0$$ and $$1$$
  • $$1$$ and $$0$$
  • $$1$$ and $$1$$
Identify the semiconductor devices whose characteristics are given above in the order $$(a), (b), (c), (d):$$

472859.png
  • Simple diode, Zener diode, Solar cell, Light dependent resistance
  • Zener diode, Simple diode, Light dependent resistance, Solar cell
  • Solar cell, Light dependent resistance, Zener diode, Simple diode
  • Zener diode, Solar cell, Simple diode, Light dependent resistance
A 5 V zener diode is used to regulate the voltage across load resistor $$R_L$$ and the input voltage varies in between 10 V to 15 V. The load current also varies from 5 mA to 50 mA. Find the value of series resistance R. 
Given, $$I_Z(min)=20 mA$$
  • $$70 \Omega$$
  • $$90.91 \Omega$$
  • $$142.86 \Omega$$
  • $$71.43 \Omega$$
Find the minimum and maximum load currents for which the zener diode as shown in figure will maintain regulation. Given, $$V_Z=10 V, R_Z=0 \Omega,  R=450 \Omega, I_Z(min)=2 mA $$ and $$I_Z(max)=60 mA$$
507024_d790fb6f28014a63b68c4089de6c1afb.png
  • $$0 mA, 33.3 mA$$
  • $$31.3 mA, 0 mA$$
  • $$2 mA, 31.3 mA$$
  • $$31.3 mA, 31.3 mA$$
In the circuit diagram given A and B are switches. The logic operation, which the switches can perform, is.....?
931543_1a85446909a64ac19cb3886fc6a4501d.JPG
  • NAND
  • OR
  • AND
  • None of these 
0:0:1


Answered Not Answered Not Visited Correct : 0 Incorrect : 0

Practice Class 12 Medical Physics Quiz Questions and Answers