What is the output Y in the following circuit, when all the three inputs A,B,C are first 0 and then 1 ?
1. 0,1
2. 0,0
3. 1,0
4. 1,1
To get output 1 for the following circuit, the correct choice for the input is
1.
2.
3.
4.
Which logic gate is represented by the following combination of logic gates?
1. OR
2. NAND
3. AND
4. NOR
In the given figure, a diode D is connected to an external resistance R = 100 Ω and an e.m.f of 3.5 V. If the barrier potential developed across the diode is 0.5 V, the current in the circuit will be
1. 30mA
2. 40mA
3. 20mA
4. 35mA
The barrier potential of a p-n junction depends on
(i)type of semiconductor material
(ii)amount of doping
(iii)temperature
Which one of the following is correct
1. (i) and (ii)only
2. (ii) only
3. (ii) and (iii)only
4. (i),(ii) and (iii)
Two ideal diodes are connected to a battery as shown in the circuit. The current supplied by the battery is
(1)0.75A
(2)zero
(3)0.25A
(4)0.5A
C and Si both have same lattice structure,having 4 bonding electrons in each.However, C is insulator whereas Si is intrinsic semiconductor. This is because
1. in case of C, the valence band is not completely filled at absolute zero temperature
2. in case of C,the condition band is partly filled even at absolute zero temperature
3. the four bonding electrons in the case of C lie in the second orbit,Whereas in the case of Si they lie in the third
4 .the four bonding electrons in the case of C lie in the third orbit, whereas for Si they lie in the fourth orbit
Transfer characteristic [output voltage vs input voltage ] for a base biased transistor in CE configuration is as shown in the figure. For using transistor as a switch, it is used:
1. in region III
2. both in region (I) and (III)
3. in region II
4. in region I
The input resistance of a silicon transistor is
100 . Base current is changed by 40
which results in a change in collector current
by 2 mA. This transistor is used as a common-
emitter amplifier with a load resistance of 4 k.
The voltage gain of the amplifier is
1. 2000
2. 3000
3. 4000
4. 1000
Symbolic representation of four logic gates
are shown as
(i)
(ii)
(iii)
(iv)
Pick out which ones are for AND, NAND and
NOT gates, respectively.
1. (iii), (ii)and (i)
2. (iii), (ii) and (iv)
3. (ii), (iv) and (iii)
4. (ii), (iii) and (iv)