# The neutral base width of a bipolar  transistor, biased  in  the active region,  is 0.5  μm. The maximum electron concentration and the diffusion constant in the base are 1014/cm3 and Dn = 25 cm2/sec respectively. Assuming negligible recombination in the base, the collector current density is (the electron charge is 1.6 x 10-19 coulomb)

1.  800 A/cm2

2.  8 A/cm2

3.  200 A/cm2

4.  2 A/cm2

4

8 A/cm2

Explanation :
No Explanation available for this question

# In a  full-wave  rectifier using  two  ideal diodes, Vdc and Vm are  the dc and peak value the voltage  respectively across a  resistive  load.  If PIV  is  the peak  inverse  voltage of diode, then the appropriate relationships for this rectifier are

1.  Vdc = (Vm/π), PIV = 2Vm

2.  Vdc = 2(Vm/π), PIV = 2Vm

3.  Vdc = 2(Vm/π), PIV = Vm

4.  Vdc = (Vm/π), PIV = Vm

4

Vdc = 2(Vm/π), PIV = 2Vm

Explanation :
No Explanation available for this question

# The minimum number of 2- to -1 multiplexers required to realize a 4-to 1 mutliplexer is

1.  1

2.  2

3.  3

4.  4

4

2

Explanation :
No Explanation available for this question

1.

2.

3.

4.

4

Explanation :
No Explanation available for this question

# 11001, 1001 and 111001 correspond  to  the 2's complement  representation of which one of the following sets of number

1.  25, 9 and 57 respectively

2.  -6, -6 and -6 respectively

3.  -7, -7 and -7 respectively

4.  -25, -9 and -57 respectively

4

-7, -7 and -7 respectively

Explanation :
No Explanation available for this question

# The 8255 Programmable Peripheral Interface is used as described below. I.  An A/D converter is interfaced to a microprocessor through an 8255. The conversion is initiated by a signal from the 8255 on Port C. A signal on Port C causes data to be strobed into Port A. II.   Two computers exchange data using a pair of 8255s. Port A works as a bidirectional data port supported by appropriate handshaking signals. The appropriate modes of operation of the 8255 for I and II would be

1.  Mode 0 for I and Mode 1 for II

2.  Mode 1 for I and Mode 0 for II

3.  Mode 2 for I and Mode 0 for II

4.  Mode 2 for I and Mode 1 for II

4

Mode 2 for I and Mode 1 for II

Explanation :
No Explanation available for this question

# The number of memory cycles required to execute the following 8085 instructions I.   LDA 3000H II.  LXI D, F0F 1H Would be

1.  2 for I and 2 for II

2.  4 for I and 3 for II

3.  3 for I and 3 for II

4.  3 for I and 4 for II

4

4 for I and 3 for II

Explanation :
No Explanation available for this question

# Consider the sequence of 8085 instructions given below. LXI H, 9258, MOV A, M, CMA, MOV M, A Which one of the following is performed by this sequence

1.  contents of location 9258 are moved to the accumulator

2.  contents of location 9258 are compared with the contents of the accumulator

3.  contents of location 8529 are complemented and stored in location 8529

4.  contents of location 5892 are complemented and stored in location 5892

4

contents of location 9258 are moved to the accumulator

Explanation :
No Explanation available for this question

# A Boolean function f of two variables x and y is defined as follows:f(0,0) = f(0, 1) = f(1, 1) = 1; f(1, 0) = 0 Assuming complements of x and y are not available, a minimum cost solution for realizing fusing only 2-input NOR gates and 2-input OR gates (each having unit cost) would have atotal cost of

1.   1 unit

2.  4 unit

3.   3 unit

4.  2 unit

4

2 unit

Explanation :
No Explanation available for this question

1.  zero Hz

2.  0.75 kHz

3.  0.5 kHz

4.  0.25 kHz

4