The unit of electric current is the Ampere (A), which measures the flow of electric charge. One ampere is equivalent to one coulomb of charge passing through a conductor per second. It is named after the French scientist André-Marie Ampère.
Which instrument measures electrical resistance?
A Ohmmeter
B Voltmeter
C Ammeter
D Wattmeter
An Ohmmeter is used to measure the resistance in an electrical circuit. Resistance is a measure of how much a component opposes the flow of current. It is measured in ohms (Ω). Voltmeters and ammeters are used to measure voltage and current, respectively.
What does a capacitor store?
A Voltage
B Current
C Power
D Charge
A capacitor stores electrical charge. It consists of two conductors separated by an insulating material (dielectric). When a voltage is applied, charge accumulates on the plates. The amount of charge stored is directly proportional to the voltage and capacitance.
What is the unit of electrical power?
A Ampere
B Ohm
C Watt
D Joule
The unit of electrical power is the Watt (W). Power is the rate at which electrical energy is used or generated. One watt equals one joule per second. It is calculated as the product of voltage (in volts) and current (in amperes).
Which type of circuit has only one path for current?
A Closed Circuit
B Series Circuit
C Parallel Circuit
D Open Circuit
A series circuit has a single path for the electric current to flow. If one component fails, the entire circuit is broken. In a series circuit, the total resistance is the sum of the individual resistances.
What is the main function of a transformer?
A To store energy
B To generate electricity
C To change voltage
D To measure current
A transformer is used to change the voltage in an AC circuit. It works on the principle of electromagnetic induction, either increasing or decreasing the voltage based on the number of turns in the primary and secondary coils.
Which law is used to calculate the current in a circuit with resistors?
A Coulomb’s Law
B Ohm’s Law
C Ampère’s Law
D Faraday’s Law
Ohm’s Law states that the current (I) in a circuit is equal to the voltage (V) divided by the resistance (R), expressed as I = V/R. This law is fundamental in calculating how current flows through resistors in a circuit.
What type of conductor follows Ohm’s Law?
A Ohmic conductor
B Non-ohmic conductor
C Diode
D Resistor
An ohmic conductor is a material that follows Ohm’s Law. It has a linear relationship between voltage and current, meaning its resistance remains constant over a range of voltages and currents. Common examples include metals like copper.
What is the purpose of grounding in electrical circuits?
A To reduce resistance
B To enhance power
C To prevent electric shocks
D To store energy
Grounding is a safety measure that directs any stray electric current safely into the earth. This helps prevent electric shocks and reduces the risk of damage to equipment in case of electrical faults or short circuits.
Which of the following devices is used to protect electrical circuits?
A Battery
B Capacitor
C Inductor
D Fuse
A fuse is a safety device used to protect electrical circuits. It contains a metal wire that melts if the current exceeds a certain level, thus breaking the circuit and preventing potential damage from overloads or short circuits.
What does an ammeter measure?
A Current
B Power
C Voltage
D Resistance
An ammeter is an instrument used to measure the current in a circuit. It is connected in series with the circuit so that all the current flows through it. Current is measured in amperes (A).
What is the unit of voltage?
A Watt
B Ampere
C Volt
D Ohm
The unit of voltage is the Volt (V). Voltage is the potential difference between two points in a circuit, which causes the flow of electric current. It is measured in volts, with one volt representing one joule of energy per coulomb of charge.
Which type of circuit has multiple paths for current to flow?
A Series Circuit
B Short Circuit
C Open Circuit
D Parallel Circuit
A parallel circuit has multiple paths for current to flow. If one path is broken, the current can still flow through other paths. This type of circuit is commonly used in household electrical wiring.
What is the primary cause of electric shock?
A Electric field
B Electric current
C High voltage
D High resistance
An electric shock occurs when an electric current flows through the human body, causing harm. The severity depends on the amount of current, the path it takes, and the duration of exposure. Voltage and resistance also affect the risk.
Which electrical component stores electrical energy?
A Capacitor
B Battery
C Resistor
D Inductor
A capacitor stores electrical energy in the form of an electrostatic field between two conductive plates separated by an insulating material. It can release stored energy when needed, and is used in applications like smoothing voltage fluctuations.