1
MCQ (Single Correct Answer)

AIPMT 2006

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.



The logic circuit gate is
A
OR gate
B
AND gate
C
NAND gate
D
NOR gate

Explanation

The truth table corresponding to waveform is given by

$$\matrix{ A & B & C \cr 1 & 1 & 1 \cr 0 & 1 & 0 \cr 1 & 0 & 0 \cr 0 & 0 & 0 \cr } $$

$$ \therefore $$ The given logic circuit gate is AND gate.
2
MCQ (Single Correct Answer)

AIPMT 2006

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 $$\mu $$A to 150 $$\mu $$A profuces a change in the collector current from 5 mA to 10 mA. The current gain $$\beta $$ is
A
50
B
67
C
75
D
100

Explanation

Current gain, $$\beta $$ = $${{\Delta {I_C}} \over {\Delta {I_B}}}$$

= $${{\left( {10 - 5} \right) \times {{10}^{ - 3}}} \over {\left( {150 - 100} \right) \times {{10}^{ - 6}}}}$$ = 100
3
MCQ (Single Correct Answer)

AIPMT 2005

In a p-n junction photo cell, the value of the photo-electromotive force profuced by monochromatic light is proportional to
A
The barrier voltage at the p-n junction.
B
The intensity of the light falling on the cell.
C
The frequency of the light falling on the cell.
D
The voltage applied at the p-n junction.

Explanation

Electromotive force depends on intensity of light that falls on it and does not depend on the frequency.
4
MCQ (Single Correct Answer)

AIPMT 2005

Copper has face centered cubic (fcc) lattice with interatomic spacing equal to 2.54 $$\mathop A\limits^ \circ $$. The value of lattice constant for this lattice is
A
2.54 $$\mathop A\limits^ \circ $$
B
3.59 $$\mathop A\limits^ \circ $$
C
1.27 $$\mathop A\limits^ \circ $$
D
5.08 $$\mathop A\limits^ \circ $$

Explanation

Lattice constant for (f.c.c.)

= a = interatomic spacing $$ \times $$ $$\sqrt 2 $$ = 3.59 $$\mathop A\limits^ \circ $$

EXAM MAP

Joint Entrance Examination

JEE Advanced JEE Main

Graduate Aptitude Test in Engineering

GATE CE GATE ECE GATE ME GATE IN GATE EE GATE CSE GATE PI

Medical

NEET

CBSE

Class 12