The unit of electric charge is the coulomb (C). One coulomb is the amount of charge transported by a constant current of one ampere in one second. It is the basic unit for charge measurement in electrical systems.
Which type of circuit has components connected end-to-end?
A Parallel circuit
B Open circuit
C Series circuit
D Closed circuit
In a series circuit, components are connected in a single path, so the current flows through each component one after the other. If one component fails, the entire circuit is interrupted, and current flow stops.
What is the main characteristic of an alternating current (AC)?
A Reverses direction periodically
B Constant flow direction
C Only flows in one direction
D Flows through resistors
Alternating current (AC) changes direction periodically, making it efficient for long-distance power transmission. The voltage alternates between positive and negative, allowing easier conversion of voltages in transformers compared to DC.
Which device is used to measure electric power?
A Ammeter
B Voltmeter
C Ohmmeter
D Wattmeter
A wattmeter measures the electric power in a circuit, which is the product of voltage and current. It is used in both AC and DC circuits and measures power in watts (W).
What is the function of a transformer?
A Convert DC to AC
B Store electrical energy
C Change voltage levels
D Measure current
A transformer is used to change the voltage in an AC circuit, either stepping up or stepping down the voltage. It works based on the principle of electromagnetic induction and does not change the frequency of the AC signal.
Which of the following is used to measure the current flowing through a circuit?
A Ammeter
B Voltmeter
C Wattmeter
D Ohmmeter
An ammeter is used to measure the current in a circuit. It is connected in series with the circuit, and its unit of measurement is amperes (A). It measures the flow of electric charge through the conductor.
Which electrical machine converts mechanical energy into electrical energy?
A Motor
B Generator
C Resistor
D Transformer
A generator converts mechanical energy into electrical energy by rotating a coil within a magnetic field. The mechanical energy can come from various sources like wind, water, or steam, which induces a current in the coil.
What does an electrical fuse protect against?
A Voltage drop
B Magnetic field
C Low current
D Current overload
An electrical fuse is designed to protect a circuit from current overload. It contains a wire that melts when the current exceeds a certain limit, breaking the circuit and preventing damage to other components.
What is the purpose of grounding in electrical systems?
A Increase current
B Store charge
C Prevent electric shock
D Control voltage
Grounding provides a safe path for excess electricity to flow into the earth, preventing electric shocks. It helps protect users and equipment by preventing dangerous voltage buildup during faults or surges.
Which component stores electrical energy in an electric field?
A Capacitor
B Resistor
C Inductor
D Diode
A capacitor stores electrical energy in the form of an electric field between two conductive plates. Capacitors are used in circuits for filtering, energy storage, and voltage regulation.
Which of the following is a characteristic of a parallel circuit?
A One path for current
B Increased total resistance
C Multiple paths for current
D Same current through all components
A parallel circuit provides multiple paths for current to flow. If one component fails, the others continue functioning. The voltage across all components in a parallel circuit remains the same.
Which of the following materials is commonly used in the construction of electrical wires?
A Rubber
B Copper
C Wood
D Glass
Copper is widely used in the construction of electrical wires due to its excellent electrical conductivity, flexibility, and resistance to corrosion. Copper wiring is efficient for power transmission and is commonly found in household and industrial applications.
Which electrical unit is used to measure power?
A Ampere
B Watt
C Volt
D Ohm
The watt (W) is the unit of power in an electrical circuit. Power is the rate at which energy is used or transferred, and it is calculated by multiplying voltage and current (P = V * I).
What type of current is supplied by most electrical outlets?
A DC
B Both
C AC
D Pulsating
Alternating current (AC) is supplied by most electrical outlets. AC changes direction periodically, making it more efficient for long-distance transmission. AC is used in household appliances, lighting, and many industrial applications.
What is the SI unit of electrical resistance?
A Ohm
B Volt
C Ampere
D Watt
The SI unit of electrical resistance is the ohm (Ω). Resistance measures how much a material opposes the flow of current. The higher the resistance, the more the material impedes current flow.