Question

1-Which statement about units is FALSE? ( )

(a) 1 ampere = 1 coulomb/second
(b) 1 volt = 1 newton /coulomb
(c) 1 farad = 1 coulomb/volt
(d) 1 henry = 1 volt-second per ampere

2-Which statement is FALSE? ( )
(a) The law of conservation of charge states that a charge can neither be
created nor destroyed, only transferred.
(b) An alternating current (ac) is a current that varies with time.
(c) By the passive sign convention, current enters through the positive
polarity of the voltage.
(d) An active element is capable of generating energy while a passive
element is not.

3-Which statement is FALSE? ( )
(a) A short circuit is a circuit element with resistance approaching zero and
an open circuit is a circuit element with resistance approaching infinity.
(b) A nonlinear resistor does not obey Ohm’s law.
(c) A network with b branches, n nodes, and l loops will satisfy the
fundamental theorem of network topology: b = l + n - 1.
(d) In a voltage divider, the source voltage v is divided among the resistors
in direct proportion to their resistances; the larger the resistance, the
larger the voltage drop.

4-Which statement is FALSE? ( )
(a) If there is a voltage source in the circuit, then we have to introduce
supernode for nodal analysis.
(b) A supernode requires the application of both KCL and KVL.
(c) Mesh analysis is not quite as general as nodal analysis because it is
only applicable to a circuit that is planar.
(d) When a current source exists between two meshes, we need to create
supermesh for mesh analysis.

5-Which statement is FALSE? ( )
(a) In general, a circuit is linear if it is both additive and homogeneous. A
linear circuit consists of only linear elements, linear dependent sources,
and independent sources.
(b) To get Thevenin equivalent circuit, we need to turn off all independent
sources in order to find out Rth and Vth.
(c) To apply Superposition Principle, firstly, we need to turn off all sources
except one source, and then find the output (voltage or current) due to
that active source using relevant techniques.
(d) When a load RL is collected to a Thevenin equivalent circuit, then the
power delivered to RL increases first and then decreases as RL increases
from 0 to infinite.

6-Which statement is TRUE ? ( )
(e) The open loop gain of an operational amplifier depends on the feedback
resistor Rf connected between the inverting input and output.
(f) An ideal op amp is an amplifier with infinite open-loop gain, zero input
resistance, and infinite output resistance.
(g) The circuit in the following figure is a difference amplifier.
(h) In an ideal op amp, the voltage across the input terminals is equal to
zero.

Answer 1

1. Which statement about units is FALSE?

The answer is (b), 1 volt = 1 newton /coulomb.

The unit of voltage is the volt (V), which is equivalent to joules per coulomb (J/C). The unit of force is the newton (N), which is equivalent to kg⋅m/s². Therefore, 1 volt = 1 J/C ≠ 1 N/C.

The other statements are all true.

2. Which statement is FALSE?

The answer is (c), By the passive sign convention, current enters through the positive polarity of the voltage.

The passive sign convention states that current flows from the positive terminal of a voltage source to the negative terminal. Therefore, current enters through the negative polarity of the voltage.

The other statements are all true.

3. Which statement is FALSE?

The answer is (b), A nonlinear resistor does not obey Ohm’s law.

Ohm's law states that the current through a resistor is directly proportional to the voltage across the resistor. A nonlinear resistor does not obey this law, and the current through the resistor is not directly proportional to the voltage across the resistor.

The other statements are all true.

4. Which statement is FALSE?

The answer is (a), If there is a voltage source in the circuit, then we have to introduce supernode for nodal analysis.

Supernodes are not necessary for nodal analysis if there are no voltage sources in the circuit. However, supernodes can be used to simplify the nodal analysis of circuits with voltage sources.

The other statements are all true.

5. Which statement is FALSE?

The answer is (d), When a load RL is collected to a Thevenin equivalent circuit, then the power delivered to RL increases first and then decreases as RL increases from 0 to infinite.

The power delivered to RL by a Thevenin equivalent circuit is constant for all values of RL. This is because the Thevenin equivalent circuit is a linear circuit, and the power delivered to a linear circuit is constant for all values of the load.

The other statements are all true.

6. Which statement is TRUE?

The answers are (f) and (h).

The open loop gain of an operational amplifier depends on the feedback resistor Rf connected between the inverting input and output.

In an ideal op amp, the voltage across the input terminals is equal to zero.

The other statements are false.