ELL 1000: Introduction to Electrical Engineering

Question

Ampere second could be the unit of:

Correct answer: Charge

Question

A utility company charges 8.2 cents/kWh. If a consumer operates a 60-W light bulb continuously for one day, how much is the consumer charged?

Correct answer: 11.8 cents

Question

If moving 16 C of charge from point b to point a requires 0.8 J. Vab the voltage drop from point a to b would be:

Correct answer: 0.05 V

Question

The conventional direction of electric current flow is:

Correct answer: opposite to the direction of flow of electrons.

Question

An automobile battery is charged with a constant current of 2A for five hours. The terminal voltage of the battery is v = 11+ 0.5t V for t > 0, where t is in hours. The energy delivered to the battery in watt-hour during the five hours is:

Correct answer: 122.5 wh

Question

Determine the total charge transferred over the time interval of 0 ≤ t ≤ 10 s when i (t) = ½ t A.

Correct answer: 25 C

Question

Find the charge that has entered the terminal of an element from t = 0 s to t = 3 s when the current entering the element is as shown in Figure 1.

Correct answer: 5 C

Question

How many joules does a 60 W light bulb consume in 1-hour?

Correct answer: 216 kJ

Question

If a constant current is passing through an inductor, the voltage across the inductor would be :

Correct answer: zero

Question

The energy stored by inductor is proportional to:

Correct answer: square of the current through it

Question

The average power consumed by a capacitor in one cycle of periodic AC signal is:

Correct answer: zero

Question

Find the equivalent inductance of the circuit of Figure 2.

Correct answer: 14 mH

Question

Determine the voltage across an inductor v(t) when the inductance is L = 250 mH, and the current is i(t)= 120 sin (500t – 30o) mA.

Correct answer: 15 sin (500t + 60o) V

Question

Find the equivalent capacitance for the circuit in Figure 3.

Correct answer: 4 mF

Question

The voltage across a 40 µF capacitor is 25 V at t0 = 0. If the current through the capacitor as a function of time is given by i(t) = 6e-6t mA for t > 0, find v(t) for t > 0.

Correct answer: 50 - 25e-6t V

Question

In forward biased condition, Diode becomes ON once applied voltage level crosses:

Correct answer: knee voltage

Question

A network has 12 branches and 8 independent loops. How many nodes are there in the network?

Correct answer: 5

Question

KCL is based on the fact that:

Correct answer: There cannot be an accumulation of charge at a node.

Question

Kirchhoff’s laws are valid for?

Correct answer: both linear and non-linear circuits.

Question

Relation between currents in Figure 8, According to KCL is:

Correct answer: i1+i5=i2+i3+i4

Question

All _____________ are loops but all _______________ are not meshes.

Correct answer: Meshes, loops

Question

Kirchhoff’s current law at a junction is based on:

Correct answer: conservation of charge

Question

If there are 10 nodes in a circuit, how many equations do we get in nodal analysis?

Correct answer: 9

Question

Kirchhoff’s voltage law in a closed path is based on:

Correct answer: conservation of energy

Question

Find Vx for the circuit shown in Figure 5.

Correct answer: 4.16 V

Question

The current Io in Figure 9 is:

Correct answer: -4 A

Question

Find the value of the node voltage v in Figure 10.

Correct answer: -12V

Question

Calculate VA-VB for the circuit shown in Figure 11.

Correct answer: 10 V

Question

Find the value of the node voltage v in Figure 16.

Correct answer: 8 V

Question

In the circuit of Figure 17, the voltage v2 is

Correct answer: 1.6 V

Question

In nodal analysis supernode in a circuit is formed when:

Correct answer: a voltage source appears between two non-reference node

Question

Which of the following statement is wrong? In node-voltage technique of solving networks, choice of reference node does not

Correct answer: affect the voltages of various nodes.

Question

Nodal analysis can be applied for________

Correct answer: Both planar and non-planar networks

Question

Determine io for the circuit shown in Figure 4.

Correct answer: 2 A

Question

A voltage source of 20 V in series with a resistance of 4 Ω can be converted into a current source and a parallel resistance with values:

Correct answer: 5 A and 4 Ω

Question

The star network is made of equal resistances of value R, then magnitude of each resistance of its equivalent delta circuit is:

Correct answer: 3R

Question

Ra is resistance at A, Rb is resistance at B, Rc is resistance at C in star connection. After transforming to delta, what is resistance between B and C?

Correct answer: Rc+Rb+(Rc*Rb/Ra)

Question

In given Figure 6, Ra, Rb and Rc are 20, 10 and 10 ohms, the values of R1, R2 and R3 are?

Correct answer: 2.5 ohms,5 ohms and 5 ohms

Question

The resistance between A and B with C open is 12 ohms (Refer Figure 7). Resistance between B and C with A open is 22 ohms. The resistance between C and A with B open is 18 ohms. The values of RA, RB and RC are?

Correct answer: 4 ohms ,8 ohms and 14 ohms

Question

In the circuit of Figure 12 , power delivered by 24 V source is:

Correct answer: 288 W

Question

All resistances are of 2 ohms (Refer Figure 13). What happens to light intensity when switch is closed?

Correct answer: Remains same

Question

The value of current I in Figure 14 is:

Correct answer: 1.7 A

Question

For the circuit shown in the Figure 25 the current I is :

Correct answer: 1 A

Question

The power delivered by 6V source in Figure 18 is:

Correct answer: 36 mW

Question

Determine the power supplied by 3 V voltage source in the circuit of Figure 19.

Correct answer: -6 mW

Question

The Thevenin resistance is found by:

Correct answer: Shorting all voltage sources and opening all current sources

Question

The Thevenin theorem is true for:

Correct answer: Linear networks

Question

Application of Norton's theorem to a circuit yield

Correct answer: Equivalent current source and impedance in parallel

Question

The Norton resistance RN is exactly __________ as that of the Thevenin resistance RTh.

Correct answer: Same

Question

Thevenin’s resistance across terminal ab for the circuit shown in Figure 22 is:

Correct answer: 5 Ω

Question

Thevenin’s voltage across terminal ab for the circuit shown in Figure 22 is:

Correct answer: 2 V

Question

Find the Thevenin equivalent voltage for the circuit shown in Figure 23.

Correct answer: 5 V

Question

Find the Norton current for the circuit shown in Figure 24.

Correct answer: 1.67 A

Question

The superposition theorem is applicable to:

Correct answer: Both current and voltage

Question

A load is connected to a network. At the terminals to which the load is connected, RTh = 10 Ω and VTh = 40 V. The maximum possible power supplied to the load is:

Correct answer: 40 W

Question

Efficiency of power transfer when maximum transfer of power occur is:

Correct answer: 50%

Question

An RC circuit has R = 2 Ω and C = 4 F. The time constant is:

Correct answer: 8 s

Question

The time constant for an RL circuit with R = 2 Ω and L = 4 H is:

Correct answer: 2 s

Question

A capacitor in an RC circuit with R = 2 Ω and C = 4 F is being charged. The time required for the capacitor voltage to reach 63.2 percent of its steady state value is:

Correct answer: 8 s

Question

An RL circuit has R = 2 Ω and L = 4 H. The time needed for the inductor current to reach 40 percent of its steady-state value is:

Correct answer: 1 s

Question

Determine the time constant for the circuit in Figure 26.

Correct answer: 1.5 µs

Question

The variable resistor R in Figure 27 is adjusted until it absorbs the maximum power from the circuit the value of R for maximum power ……….. Ω

Correct answer: 25 kΩ

Question

In the circuit of Figure 28, the capacitor voltage just before t = 0 is:

Correct answer: 4 V

Question

Consider the circuit given in Figure 29, Find steady state of i(t) if v(t) = 20 V.

Correct answer: 5 A

Question

Find the time constant of the circuit shown in Figure 30.

Correct answer: 250 µs

Question

An RC circuit is an example of :

Correct answer: First order circuit