This set of Electronic Devices and Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Basic Concepts”.

1. A solid copper sphere, 10 cm in diameter is deprived of 1020 electrons by a charging scheme. The charge on the sphere is

a) 160.2 C

b) -160.2 C

c) 16.02 C

d) -16.02 C

View Answer

Explanation: n 10

^{20}, Q = ne = e 10

^{20}= 16.02 C.

Charge on sphere will be positive.

2. 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

a) 13.33 C

b) 75 C

c) 1500 C

d) 1.5 C

View Answer

Explanation: dQ = i dt = 15000 x 100µ = 1.5 C.

3. If 120 C of charge passes through an electric conductor in 60 sec, the current in the conductor is

a) 0.5 A

b) 2 A

c) 3.33 mA

d) 0.3 mA

View Answer

Explanation: i = dQ/dt = 120/60 = 2A.

4. The energy required to move 120 coulomb through

3 V is

a) 25 mJ

b) 360 J

c) 40 J

d) 2.78 mJ

View Answer

Explanation: W = Qv = 360 J.

5. Consider the circuit graph shown in figure below. Each branch of circuit graph represent a circuit element. The value of voltage V1 is

a) 30 V

b) 25 V

c) 20 V

d) 15 V

View Answer

Explanation: 100 = 65 + V2 => V2 = 35 V

V3 – 30 = V2 => V3 = 65 V

105 – V3 + V4 – 65 = 0 => V4 = 25 V

V4 + 15 – 55 + V1 = 0 => V1 = 15 V.

6. Req = ?

a) 11.86 ohm

b) 10 ohm

c) 25 ohm

d) 11.18 ohm

View Answer

Explanation: Req – 5 = 10(Req + 5)/(10 + 5 +Req). Solving for Req we have Req = 11.18 ohm.

7. In the circuit the dependent source

a) supplies 16 W

b) absorbs 16 W

c) supplies 32 W

d) absorbs 32 W

View Answer

Explanation: P = VIx = 2Ix Ix = 2 x 16 or 32 watt (absorb).

8. Twelve 6 resistor are used as edge to form a cube. The resistance between two diagonally opposite corner of the cube is (in ohm)

a) 5/6

b) 6/5

c) 5

d) 6

View Answer

9. The energy required to charge a 10 µF capacitor to 100 V is

a) 0.1 J

b) 0.05 J

c) 5 x 10^{(-9)} J

d) 10 x 10^{(-9)} J

View Answer

Explanation: Energy provided is equal to 0.5 CVxV.

10. 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

a) 0.75 mF

b) 1.33 mF

c) 0.6 mF

d) 1.67 mF

View Answer

Explanation: Voltage gain = 1/C x i(t2 – t1), where t2 – t1 = 10s. Hence C = 1.67 mF.

**Sanfoundry Global Education & Learning Series – Electronic Devices and Circuits.**

To practice all areas of Electronic Devices and Circuits, __here is complete set of 1000+ Multiple Choice Questions and Answers__.