Contents
NEET Physics Chapter Wise Mock Test – Electronic devices
Question 1.
In the figure shown below, which of the diodes are forward biased?
(a) 1,2, 3
(b) 2, 4,5
(c) 1, 3, 4
(d) 2, 3, 4
Question 2.
A Zener diode is used for
(a) rectification
(b) modulation
(c) detection
(d) Voltage Regulation
Question 3.
In the figure, the input is across the terminals A and C and the output is across B and D. Then, the output is
(a) zero
(b) same as the input
(c) full wave rectified
(d) half wave rectified
Question 4.
In a good conductor of electricity, the type of bonding that exists is
(a) ionic
(b) van der Waal
(c) covalent
(d) metallic
Question 5.
In a junction diode, the holes are due to
(a) missing electron
(b) extra neutron
(c) protons
(d) All of these
Question 6.
If control grid is made negative, then the plate current will
(a) increase
(b) remain constant
(c) decrease
(d) cannot say from given data
Question 7.
If in a diode valve, the plate potential becomes double, then plate current will be
(a) 2√2 times
(b) 8 times
(c) 3√3 times
(d) 2 times
Question 8.
A p-n-p transistor is said to be in active region of operation, when
(a) both emitter junction and collector junction are forward biased
(b) both emitter junction and collector junction are reverse biased
(c) emitter junction is forward biased and collector junction is reverse biased
(d) emitter junction is reverse biased and collector junction is forward biased
Question 9.
A n-p-n transistor conducts, when
(a) collector is positive and emitter is at same potential as the base
(b) both collector and emitter are negative with respect to the base
(c) both collector and emitter are positive with respect to the base
(d) collector is positive and emitter is negative with respect to the base
Question 10.
To get an output Y =1 from the circuit shown, the inputs A ,B and C must be respectively
(a) 0,1,0
(b) 1,0,0
(c) 1,0,1
(d) 1,1,0
Question 11.
An AND gate is followed by a NOT gate in series. With two inputs A and B, the Boolean expression for the output Y will be
Question 12.
In the CB mode of a transistor, when the collector voltage is changed by 0.5 V. The collector current changes by 0.05 mA. The output resistance will be
(a) 10 kΩ
(b) 20 kΩ
(c) 5 kΩ
(d) 2.5 kΩ
Question 13.
The current gain of a transistor in common emitter mode is 49. The change in collector current and emitter current corresponding to the change in base current by 5.0 μA, will be
(a) 245 μA, 250 μA
(b) 240 μA, 235 μA
(c) 260 μA, 255 μA
(d) None of the above
Question 14.
The following configuration of gate is equivalent to
(a) NAND
(b) XOR
(c) OR
(d) None of these
Question 15.
The following circuit represents
(a) OR gate
(b) XOR gate
(c) AND gate
(d) NAND gate
Question 16.
The truth table is given below represents
(a) AND gate
(b) NOR gate
(c) OR gate
(d) NAND gate
Question 17.
If internal resistance of cell is negligible, then current flowing through the circuit is
(a) 3/50 A
(b) 5/50 A
(c) 4/50 A
(d) 2/50 A
Question 18.
For a transistor Ic/Ie = 0.96 the current gain common-emitter configuration is
(a) 6
(b) 12
(c) 24
(d) 48
Question 19.
For a given circuit of ideal p-n junction diode, which of the following is correct ?
(a) In forward biasing the voltage across R is V
(b) In reverse biasing the voltage across R isV
(c) In forward biasing the voltage across R is 2V
(d) In reverse biasing the voltage across R is 2V
Question 20.
Identify the operation performed by the circuit given below
(a) NOT
(b) AND
(c) OR
(d) NAND
Question 21.
In the following circuit, the output Y becomes zero for the inputs
(a) A=1, B=0, C=0
(b) A=0,B= 1,C=1
(c) A=0,B=0,C=0
(d) A=1, B=1, C=1
Direction (Q.NOs.22-27): In each of the following questions a statement of Assertion is given followed by a corresponding statement of Reason just below it. Of the statements mark the correct answer as
(a) If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
(b) If both Assertion and Reason are true but the Reason is not correct explanation of the Assertion
(c) If Assertion is true but Reason is false
(d) If both Assertion and Reason are false
Question 22.
Assertion (A): In a common emitter transistor amplifier, the input current is much less than the output current.
Reason (R): The common emitter transistor amplifier has very high input impedance.
Question 23.
Assertion (A): The logic gate NOT can be built using diode.
Reason (R): The output voltage and the input voltage of the diode have 180° phase difference.
Question 24.
Assertion (A): A transistor amplifier in common emitter configuration, has a low input impedance.
Reason (R): The base to emitter region is forward biased.
Question 25.
Assertion (A): NAND or NOR gates are called digital building blocks.
Reason (R): The repeated use of NAND or NOR gate can produce all the basic or completed gates.
Question 26.
Assertion (A): The resistivity of a semiconductor increases with temperature.
Reason (R): The atoms of a semiconductor vibrate with larger amplitudes of higher temperatures there by increasing its resistivity.
Question 27.
Assertion (A): The value of current through p-n junction in the adjoining figure will be 10 mA.
Reason (R): In the above figure, p-side is at higher potential than n-side.
Question 28.
The following configuration of gate is equivalent to figure
(a) NAND
(b) XOR
(c) OR
(d) None of these
Question 29.
In the figure, potential difference between A and B is
(a) zero
(b) 5V
(c) 10V
(d) 15V
Question 30.
The diode used in the circuit shown in the figure, has a constant voltage drop of 0.5 V at all currents and a maximum power rating of 100 mW. What should be the value of the resistor R, connected in series with the diode for obtaining maximum current?
(a) 1.5Ω
(b) 5Ω
(c) 6.67Ω
(d) 200Ω
Question 31.
In a common emitter transistor, the base current Ib = 2 μA, α=0.9, then Ic is equal to
(a) 18 μA
(b) 20 μA
(c) 22 μA
(d) 24 μA
Question 32.
An n-p-n transistor circuit is arranged as shown in figure. It is
(a) a common base amplifier circuit
(b) a common emitter amplifier circuit
(c) a common collector amplifier circuit
(d) Neither of the above
Question 33.
The junction diode in the following circuit requires a minimum current of 1 mA to be above the knee point (0.7 V) of its I-V characteristic curve. The voltage across the junction diode is independent of current above the knee point, if VB=4V, then the maximum value of R, so that the voltage is above knee point will be .
(a) 3.3 kΩ
(b) 4.0 kΩ
(c) 4.7 kΩ
(d) 6.6 kΩ
Question 34.
The circuit shown in the figure contains two diodes, each with a forward resistance of 30Ω and with infinite backward resistance. If the battery is 3 V, the current through the 50Ω resistance (in ampere) is
(a) zero
(b) 0.01
(c) 0.02
(d) 0.03
Question 35.
In the network shown, the current flowing through the battery of negligible internal resistance, is
(a) 0.10 A
(b) 0.15 A
(c) 0.20 A
(d) 0.30 A
Question 36.
The output Y of the logic circuit shown in figure, is best represented as
Question 37.
A p-n junction (D) shown in the figure can act as a rectifier. An alternating current source (V) is connected in the circuit. The current (I) in the resistor (R) can be shown by
Question 38.
In the circuit as shown in figure, A and B represent two inputs and C represents the
(a) OR gate
(b) NOR gate
(c) AND
(d) NAND gate
Question 39.
The ratio of electron and hole current in a semiconductor is 7/4 and the ratio of drift velocities of electrons and holes is 5/4, then ratio of concentrations of electrons and holes will be
(a) 5/7
(b) 7/5
(c) 25/49
(d) 49/25
Question 40.
In a junction diode, the direction of diffusion current is
(a) from n-region to p-region
(b) from p-region to n-region
(c) from n-region to p-region, if the junction is forward biased and vice versa, if it is reverse biased
(d) from p-region to n-region if the junction is forward biased and vice versa, if it is reversed biased
Question 41.
The direction of flow of current in the given diagram is
(a) zero
(b) 10-2 A
(c) 10A
(d) 0.025A
Answers:
Hints And Solutions:
