Electronic Devices and Circuits

Basic Concepts

Question 1
Marks : +2 | -2
Pass Ratio : 100%
A lightning bolt carrying 15,000 A lasts for 100 s. If the lightning strikes an airplane flying at 2 km, the charge deposited on the plane is _________
13.33 C
75 C
1500 C
1.5 C
Explanation:
dQ = i dt = 15000 x 100µ = 1.5 C.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
The energy required to charge a 10 µF capacitor to 100 V is ________
0.1 J
0.05 J
5 x 10(-9) J
10 x 10(-9) J
Explanation:
Energy provided is equal to 0.5 CVxV.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
Consider the circuit graph shown in figure below. Each branch of circuit graph represent a circuit element. The value of voltage V1 is:
30 V
25 V
20 V
15 V
Explanation:
100 = 65 + V2 => V2 = 35 V
Question 4
Marks : +2 | -2
Pass Ratio : 100%
A solid copper sphere, 10 cm in diameter is deprived of 1020 electrons by a charging scheme. The charge on the sphere is _________
160.2 C
-160.2 C
16.02 C
-16.02 C
Explanation:
n 1020, Q = ne = e 1020 = 16.02 C.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
The energy required to move 120 coulomb through 3 V is _________
25 mJ
360 J
40 J
2.78 mJ
Explanation:
W = Qv = 360 J.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
A capacitor is charged by a constant current of 2 mA and results in a voltage increase of 12 V in a 10 sec interval. The value of capacitance is ________
0.75 mF
1.33 mF
0.6 mF
1.67 mF
Explanation:
The capacitor current is given as i=C*(dv/dt), where dv/dt is the derivative of voltage, dt=t2-t1 given as 10 sec and dv is the change in voltage which is given as 12V.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
If 120 C of charge passes through an electric conductor in 60 sec, the current in the conductor is _________
0.5 A
2 A
3.33 mA
0.3 mA
Explanation:
i = dQ/dt = 120/60 = 2A.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
In the circuit the dependent source __________
supplies 16 W
absorbs 16 W
supplies 32 W
absorbs 32 W
Explanation:
P = VIx = 2Ix Ix = 2 x 16 or 32 watt (absorb).
Question 9
Marks : +2 | -2
Pass Ratio : 100%
What will be the value of Req in the following Circuit?
11.86 ohm
10 ohm
25 ohm
11.18 ohm
Explanation:
We infer from the given diagram that the same pattern is followed after every 10ohm resistor. The infinite pattern in parallel as a whole is considered as to be Rx.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
Twelve 6 ohm resistors are used to form an edge of a cube. The resistance between two diagonally opposite corner of the cube (in ohm) is ________
5/6
6/5
5
6
Explanation: