The question asks to identify the type of resistor suitable for a given rating of 10 ohms and 10 watts. The power rating is a crucial factor in determining the appropriate resistor type.
C) Wire wound resistor — Wire-wound resistors are specifically designed for high power dissipation due to their construction using resistive wire and often a ceramic core, allowing them to handle power ratings of \(10 \, \text{W}\) and much higher.
The question asks about the resistance of a few meters of wire conductor in a closed electrical circuit. We need to consider the typical properties of conductors used in circuits.
Correct Option: A) Practically zero
For a few meters of wire conductor in a closed electrical circuit, the resistance is designed to be extremely small. While not absolutely zero, it is considered "practically zero" because its effect on the overall circuit is negligible compared to other components. This ensures efficient transmission of electrical energy.
This problem involves understanding the relationship between power, resistance, and current in a series circuit. When components are connected in series, the current flowing through them is the same. The power dissipated by a component is given by \(P = I^2 R\), where \(I\) is the current and \(R\) is the resistance. We need to analyze how replacing one bulb affects the total resistance, the current in the circuit, and consequently, the heat output of the heater.
Correct Option: B) Increase
This question asks why a glass rod gets charged when rubbed with a silk cloth. This phenomenon is known as charging by friction or triboelectric charging. It involves the transfer of charge carriers between two materials when they are rubbed together.
C) It gives away electrons. When a glass rod is rubbed with a silk cloth, the glass rod loses electrons to the silk cloth. Since electrons are negatively charged, the loss of electrons leaves the glass rod with a net positive charge.
The question asks about the connection type for bulbs in street lighting. This is a common application of electrical circuits, and understanding the properties of series and parallel connections is crucial.
Correct Option: A) Bulbs in street lighting are all connected in Parallel. This ensures that each bulb receives the full supply voltage and can operate independently. If one bulb fails, the others continue to function, which is essential for maintaining illumination on streets.
The question asks for a method used for the absolute measurement of resistances. Absolute measurement implies determining a quantity directly from fundamental units or by comparison with standards, without relying on pre-calibrated instruments. We need to evaluate each option based on this definition.
Correct Option: D) Wheatstone bridge method — The Wheatstone bridge is a classic method for the precise and absolute measurement of unknown electrical resistances. By balancing the bridge, the unknown resistance can be determined from the known values of the other three resistances, often standard resistors, without requiring prior calibration of the measuring device itself.