Introduction to Electrical Engineering MCQs (Part-10)
What is electric potential?
A Force per unit charge
B Energy per unit charge
C Charge per unit area
D Energy per unit mass
Electric potential refers to the electric potential energy per unit charge. It is the work done to move a unit charge from a reference point (usually infinity) to a specific point in an electric field, measured in volts (V).
What is electric flux?
A Resistance to current
B Flow of charge
C Flow of electric field
D Movement of electrons
Electric flux is the measure of the flow of the electric field through a given surface. It is the product of the electric field strength and the area through which the field lines pass, and is measured in volt-meters (Vm).
What is the unit of electric potential?
A Volt
B Ohm
C Watt
D Ampere
The unit of electric potential is the Volt (V), which is defined as one joule of energy per one coulomb of charge. It represents the potential difference that drives current in a circuit.
What is the relationship between electric potential and electric field?
A Independent
B Directly proportional
C Unrelated
D Inversely proportional
Electric potential is inversely proportional to the electric field. The electric field is the gradient of the electric potential, meaning it points in the direction of decreasing potential. A stronger field corresponds to a greater change in potential over a given distance.
What is the primary function of an electric field?
A To attract charges
B To repel charges
C To move charges
D To store charges
An electric field exerts a force on electric charges, causing them to move. This movement of charges is what creates an electric current in a conductor, and is fundamental in the operation of electrical devices.
How is electric potential energy related to electric potential?
A Dependent on charge only
B Directly proportional
C Inversely proportional
D Unrelated
Electric potential energy is directly proportional to the electric potential and the charge of an object. The energy is given by the formula U = qV, where U is electric potential energy, q is charge, and V is electric potential.
What is the principle behind the concept of electric potential?
A Current flow
B Force per unit charge
C Work done in moving charge
D Energy per unit mass
Electric potential is based on the work required to move a unit charge from one point to another against an electric field. The work done per unit charge defines the potential difference between the two points.
What does Gauss’s Law relate to?
A Electric field and charge distribution
B Magnetic field and current
C Power and energy
D Current and voltage
Gauss’s Law relates the electric field to the charge distribution. It states that the electric flux through a closed surface is proportional to the total charge enclosed within that surface. This law is fundamental in electrostatics and integral to Maxwell’s equations.
What happens to the electric flux when the angle between the electric field and the surface is 90°?
A Flux remains constant
B Flux becomes zero
C Flux doubles
D Flux increases
Electric flux is zero when the angle between the electric field and the surface is 90°. This is because the electric field lines are perpendicular to the surface, and no field passes through the surface. Flux is maximized when the angle is 0°.
What is the relationship between electric flux and electric field strength?
A Dependent on surface area
B Directly proportional
C Inversely proportional
D Unrelated
Electric flux is directly proportional to both the electric field strength and the area through which the field passes. The greater the field strength or the larger the area, the higher the flux. Flux also depends on the angle between the field and surface.
What does a voltmeter measure?
A Power
B Current
C Voltage
D Resistance
A voltmeter measures the electric potential difference (voltage) between two points in a circuit. It is connected in parallel with the component or section of the circuit where the voltage is to be measured.
What causes the electric field around a charged object?
A The charge itself
B Resistance
C Magnetic field
D Current flow
The electric field around a charged object is created by the charge itself. The strength of the electric field depends on the magnitude of the charge and the distance from the charge, and it exerts a force on other charges within the field.
What happens to the electric potential when the distance from a point charge is doubled?
A It stays the same
B It doubles
C It quadruples
D It halves
The electric potential due to a point charge is inversely proportional to the distance from the charge. As the distance increases, the potential decreases. Specifically, if the distance is doubled, the potential is halved.
What is the role of the electric field in electrical circuits?
A To store energy
B To move electrons
C To limit current
D To control voltage
The electric field in a circuit exerts a force on the electrons, causing them to move. This movement of electrons constitutes the current, and the electric field drives the flow of charge through the circuit, powered by the voltage difference.
What is the electric potential at infinity?
A One
B Infinity
C Zero
D Depends on charge
At infinity, the electric potential is considered zero. This is the reference point from which electric potential differences are measured. The potential at a point decreases as the distance from the charge increases, and it is zero at infinite distance.