Electronic Science - Online Test
Q1. when two capacitors are put in series, the equivalent capacitance is
Answer : Option C
Explaination / Solution:
When two capacitors C1 and C2 are connected in series, the reciprocal of the equivalent capacitance in series is equal to the sum of the reciprocals of the two individual capacitances.
It has value lesser than the least value of capacitance.
It has value lesser than the least value of capacitance.
Q2. The output expression for the Karnaugh map shown below is
Answer : Option B
Explaination / Solution:
Q3. Group
I gives two possible choices for the impedance Z in the diagram. The circuit
elements in Z satisfy the conditions R2C2 > R1C1. The transfer functions V0/V1 represents a kind of
controller.
Match the impedances in Group I with the type of controllers in Group II
Group I Group II
Answer : Option B
Explaination / Solution:
Q4. The cross section of a JFET is shown in the following figure. Let Vc be -2
V and let VP be the initial pinch -off voltage. If the width W is doubled (with
other geometrical parameters and doping levels remaining the same), then the
ratio between the mutual trans conductances of the initial and the modified
JFET is
Answer : Option C
Explaination / Solution:
Q5. For the circuit shown in the figure below, assume that diodes D1, D2 and D3 are ideal.
The DC components of voltages v1 and v2, respectively are
Answer : Option B
Explaination / Solution:
Q6. For measuring μA current the galvanometer is
Answer : Option C
Explaination / Solution:
For measurement of current of any magnitude, the galvanometer is always connected in series. This is to ensure that the entire current flows through the galvanometer. If the galvanometer were connected in parallel, the current branches out and only a part of the current will flow through it.
Q7. Consider the Boolean operator # with the following properties:
Then x # y is equivalent to
Then x # y is equivalent to
Answer : Option A
Explaination / Solution:
No Explaination.
Q8. A Wheatstone bridge ABCD is balanced with a galvanometer between the points B and D. At balance the resistance between the points B and D is :
Answer : Option D
Explaination / Solution:
No current passes through the Galvanometer in the bridge balance condition.
Therefore, the resistance between B and D is infinite.
Q9. permanent magnets should have
Answer : Option B
Explaination / Solution:
No Explaination.
Q10. In an insulator, the forbidden energy gap between the valance band and conduction band is of the order of
Answer : Option B
Explaination / Solution:
In an insulator, the forbidden energy gap is very large.In general, the forbidden energy gap is more than 5eV and almost no electrons are available for conduction. Therefore, a very large amount of energy must be supplied to a valence electron to enable it to move to the conduction band.
In the case of materials like glass, the valence band is completely filled at 0 K. The energy gap between valence band and conduction band is of the order of 10 eV. Even in the presence of high electric field, the electrons cannot move from valence band to conduction band.
