NEET Free Online Mock Test - 2019

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NEET Physics  Semiconductor Electronics: Materials, Devices & Circuits  Practice Q & A

1. A transistor is operated in common emitter configuration at constant collector voltage Vc = 1.5 V such that a change in the base current from 100 μA to 150 μA produces a change in the collector current from 5 mA to 10 mA. The current gain (β) is:

 67 75 100 50

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2. In semiconductors at a room temperature

 The valence band is completely filled and the conduction band is partially filled The valence band is completely filled The conduction band is completely empty The valence band is partially empty and the conduction band is partially filled

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3. In a full wave rectifier circuit operating from 50 Hz mains frequency, the fundamental frequency in the ripple would be

 50 Hz 25 Hz 100 Hz 70.7 Hz

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4. For CE transistor amplifier, the audio signal voltage across the collector resistance of 2 kΩ is 4 V. If the current amplifier">amplification factor of the transistor is 100 and the base resistance is 1 kΩ, then the input signal voltage is

 10 mV 20 mV 30 mV 15 mV

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5. The given circuit has two ideal diodes connected as shown in the figure below. The current flowing through the resistance R1 will be
circuit with two ideal diodes.png" alt="circuit with two ideal diodes" style="margin:0 auto;" />

 2.5 A 10.0 A 1.43 A 3.13 A

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6. Consider the junction diode as ideal. The value of current flowing through AB is

 10–1 A 10–3 A 0 A 10–2 A

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7. If a, b, c, d are inputs to a gate and x is its output, then, as per the following time graph, the gate is:

 AND OR NAND NOT

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8. The given truth table is for which logic gate:

ABY
110
011
101
001

 NAND XOR NOR OR

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9. The following figure shows a logic gate circuit with two inputs A and B and the output C. The voltage waveforms of A, B and C are as shown below
circuit voltage waveforms.png" alt="logic gate circuit voltage waveforms" style="margin:0 auto;" />
The logic circuit gate is:

 AND gate NAND gate NOR gate OR gate

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