NEW
Font size
WorksheetsCâu hỏi về điện trường và tụ điện
Total questions: 47
Worksheet time: 24mins
A point charge q moves in an electric field along a closed curve, then the work done by the electric field force
is proportional to the length of the path.
is non-zero if the electric field is not uniform.
depends on the shape of the path.
is always zero.
Each capacitor has a.........written on it, when the capacitor is connected beyond this value, the capacitor becomes a conductor (the capacitor is punctured)
Limit capacitance
Limit charge
Limit electric field
Limit voltage
According to Coulomb's law about the interaction between two point charges
the magnitude of the interaction force is directly proportional to the product of the magnitudes of the two charges.
the magnitude of the interaction force is directly proportional to the square of the distance between them.
the interaction force is directly proportional to the dielectric constant.
the interaction force is inversely proportional to the distance between them.
The form of matter existing around a charge created by that charge and characterizing the transmission of interaction between charges is called
electric field.
electric potential.
static electric potential energy.
electric charge.
Two points M and N lie on the same field line of a uniform electric field with intensity E, the potential difference between M and N is UMN, the distance MN = d. Which of the following formulas is incorrect?
UMN = VM - VN.
UMN = E.d
AMN = q.UMN
E = UMN.d
A capacitor with capacitance is charged, the energy of the electric field that this capacitor has is
.
.
.
.
Which of the following diagrams correctly represents the electric field lines of a positively charged sphere?
.
.
.
.
The force acting on a charge to make it deviate towards the positive plate (as shown in the figure) is which force?
Gravitational force.
Frictional force.
Electric force.
Gravitational attraction.
When a charge moves into a uniform electric field perpendicular to the electric field lines, which factor will always remain constant?
Acceleration of motion.
Direction of motion.
Speed of motion.
Displacement after a unit time.
A capacitor is a system consisting of two conductors
placed close together and connected by a metal wire.
placed close together and separated by an insulating layer.
in contact with each other and surrounded by a dielectric.
placed parallel and separated by another conductor.
A capacitor with capacitance C, charge q, voltage U. If the voltage across the capacitor plates is doubled, then the charge of the capacitor
remains unchanged.
doubles.
quadruples.
is halved.
The energy of the electric field in a capacitor that has accumulated charge q does not depend on
the charge that the capacitor has accumulated.
the voltage between the two capacitor plates.
the time taken to charge the capacitor.
the capacitance of the capacitor.
The electric field intensity at a point M in any electric field is a quantity
a vector, with direction, magnitude depending on the position of point M.
a scalar, always positive.
a vector, only magnitude depending on the position of point M.
a scalar, can have negative or positive values.
The potential energy of an electric charge q placed at point M in any electric field does not depend on
the charge q.
the position of point M.
the electric field.
the mass of the charge q.
In which of the following cases is the external circuit voltage not equal to the electromotive force of the power source?
The current through the source is 0.
Closed circuit and the internal resistance of the source is not 0.
Closed circuit and the internal resistance of the source is 0.
The external circuit is open.
For a closed circuit with a power source and an external resistance, the current in the circuit
Decreases when the external resistance increases.
Is inversely proportional to the external resistance.
Increases when the external resistance increases.
Is directly proportional to the external resistance.
The heat generated on a conductor when an electric current passes through it
is directly proportional to the current flowing through the conductor.
is directly proportional to the square of the current flowing through the conductor.
is inversely proportional to the current flowing through the conductor.
is inversely proportional to the square of the current flowing through the conductor.
The electromotive force of a power source is a quantity characteristic of its ability to
do work of the power source.
store electric charge of the power source.
exert force of the power source.
charge the two terminals of the power source.
In the experiment to measure the electromotive force and internal resistance of an electrochemical cell, we must connect an additional resistor R0 in series with the electrochemical cell to:
Avoid the case where the current through the source is too large (short circuit).
Because the resistance of the voltmeter is very small.
To create a sufficiently large current for the meter to operate.
To make the measurement result more accurate.
When starting a motorcycle, one should not press the start button for too long and repeatedly because
the prolonged short circuit current will generate heat and damage the battery.
too much energy is consumed.
the starter motor will wear out quickly.
the start button will break.
The efficiency of a power source is determined by
the ratio of useful work to the total work of the current in the circuit.
the ratio of total work to useful work generated in the external circuit.
the work of the current in the external circuit.
the heat generated in the entire circuit.
When the external circuit is open, the voltage between the two terminals of the power source
is greater than the electromotive force of the power source.
is equal to the product of the current and the internal resistance of the source.
is equal to the electromotive force of the power source.
is less than the electromotive force of the power source.
The electric current in metals is a directed flow of:
negative ions, free electrons opposite to the electric field.
free electrons opposite to the electric field.
ions, electrons in the electric field.
electrons and holes in the direction of the electric field.
What is the main cause of the resistance of metals?
The free electrons colliding with the disorder of positive ions in the lattice.
The free electrons colliding with each other during chaotic thermal motion.
The positive ions in the lattice colliding with each other during chaotic thermal motion.
The positive ions moving directionally under the influence of the electric field with electrons.
What is the expression for the dependence of resistivity on temperature?
R =
R = R0(1 + αt).
Q = I2Rt.
ρ = ρ0(1+αt).
How does the drift velocity of electrons change along a wire with a decreasing cross-section?
Decreases as the cross-section of the wire decreases.
Increases as the cross-section of the wire decreases.
Remains unchanged.
Not enough information to answer.
What is a variable resistor?
A resistor that can change its value and is used to adjust the direction of current in a circuit.
A resistor that can change its value and is used to adjust the intensity and direction of current in a circuit.
A resistor that can change its value and is used to adjust the intensity of current in a circuit.
A resistor that does not change its value and is used to adjust the intensity of current in a circuit.
The V-I characteristic curve represents the dependence of the current through a resistor on the voltage across the conductor. What shape does this curve take?
Elliptical.
Straight.
Hyperbolic.
Parabolic.
In a circuit with current I, the amount of charge q that passes through the circuit in time t is determined by which expression?
q = I.t.
q = I/t
q = t/I
q = I2.t.
What is the characteristic of a thermal resistor with a temperature coefficient?
Positive when the temperature increases, the resistance increases.
Positive when the temperature increases, the resistance decreases.
Negative when the temperature increases, the resistance increases.
Negative when the temperature increases, the resistance decreases to zero.
Which conclusion is correct regarding the effect of a power source?
Used to create and maintain voltage to sustain current in a circuit.
Used to create negative ions.
Used to create positive ions.
Used to create negative ions that flow in the conductor.
What does the voltage marked on an ALKALINE battery, 12 V, indicate?
Capacitance.
Power source.
Work done by the power source.
Electromotive force of the source.
The conventional direction of current is the direction of the drift of which particles?
Electrons
Neutrons
Negative charges
Positive charges
In the electricity bill, the value-added tax (VAT) of the electricity company indicates that the consumed electricity is 272 units, which means?
272 kWh.
272 Wh.
272 kW/h.
272 W/h.
The electricity consumption is 272 kWh.
272 kWh.
272 Wh.
272 kW/h.
272 W/h.
Which device completely converts energy into thermal energy when it operates?
Incandescent bulb.
Electric fan.
Electric kettle.
Battery being charged.
If the magnitude of the electric charge of one of the two charged objects is halved, while the distance between them remains unchanged, what will happen to the electric interaction force between the two objects?
decrease by 2 times.
decrease by 4 times.
decrease by 8 times.
remain unchanged.
The expression relating current intensity to density and speed of charged particles is
I = Snv
I = Sve
I = nve/S
I = Snve
The work of the power source is
the amount of electric charge generated by the power source in 1 second.
the work done by an external force to move the charge inside the source.
the work done by the current in a closed circuit generated in 1 second.
the work done by the current when moving one unit of charge in a closed circuit.
The counting number of the household electricity meter indicates
the electric power used by the household.
the time the household has used electricity.
the amount of electricity consumed by the household.
the number of household appliances used.
The rated power of electrical devices is
the maximum power that the device can achieve.
the minimum power that the device can achieve.
the power achieved when it operates normally.
the average power of the device.
The physical quantity that characterizes the strength of the electric current is
electric charge.
electric current.
electron density.
current intensity.
The unit of measurement for resistance is
ohm (Ω).
farad (F).
henry (H).
watt (W).
The characteristic of thermal resistors with a temperature coefficient of resistance
is positive when the temperature increases, the resistance increases.
is positive when the temperature increases, the resistance decreases.
is negative when the temperature increases, the resistance increases.
is negative when the temperature increases, the resistance decreases to zero.
Let A be the work done by an external force moving the charge q through the source. The electromotive force of the source is:
E = q/A
E = q.A
E = A/q
E = - q/A
Which device is used to measure electricity consumption?
Ammeter.
Electric meter.
Voltmeter.
Electrostatic meter.
On household electrical devices, it is often marked 220V and the wattage (W). What does this wattage mean?
The power consumption of the device when it is used with a voltage lower than 220V.
The power consumption of the device when it is used with the correct voltage of 220V.
The work done by the current in one minute when this device is used with the correct voltage of 220V.
The electrical energy consumed by the device in one hour when it is used with the correct voltage of 220V.
