Every question from this NCERT chapter, with a detailed explanation.
Which one of the following correctly states the dependence of resistance of a uniform metallic conductor?
Which of the following statements regarding alloys and electrical properties is/are correct? 1. Alloys generally have higher resistivity than their constituent metals. 2. Alloys oxidise rapidly at high temperatures compared to pure metals.
If the length of a wire is doubled while keeping its cross-sectional area constant, what happens to its resistance?
What is the direction of conventional current flow in an external circuit connecting a cell?
Which of the following expressions correctly defines one ampere?
Consider the following pairs regarding basic electrical devices and their typical connection placement: 1. Ammeter : Parallel 2. Voltmeter : Parallel 3. Fuse : Series 4. Rheostat : Series Which of the pairs given above are correctly matched?
Assertion (A): Resistivity is a characteristic property of a material. Reason (R): The resistivity of a metal is independent of its temperature.
Consider the following pairs regarding basic electrical devices and their typical connection placement: 1. Ammeter - series 2. Voltmeter - parallel 3. Fuse - series 4. Rheostat (variable resistance) - in series to regulate current Which one of the following combinations is correct?
With reference to electric current in metallic circuits, consider the following statements: 1. Electrons constitute the mobile charge carriers in metallic wires. 2. The conventional direction of current is the same as the direction of electron flow. 3. A closed conducting path is not required for a continuous flow of current. Which of the statements given above is/are correct?
A charge of 300 C passes through a cross-section of a conductor in 5 minutes. The current is closest to which of the following?
Assertion (A): An ammeter is connected in series in a circuit. Reason (R): An ammeter must have a very high resistance to measure current accurately.
Which one of the following correctly defines one volt?
In practical circuits, a component used to regulate current without altering the source voltage is known as:
Consider the following statements about electrical resistivity: 1. It is a characteristic property of a material. 2. Its SI unit is ohm per metre. 3. It varies with changes in temperature. Which of the statements given above is/are correct?
For a wire of given material, if diameter is doubled while length remains the same, how does the resistance change?
Consider the following statements about a series connection of resistors: 1. The current passing through each resistor varies according to its resistance. 2. The sum of individual potential drops equals the total applied potential difference. Which of the statements given above is/are correct?
In a series combination of resistors, the equivalent resistance is equal to:
Consider the following statements about a parallel network of resistors: 1. The potential difference across each branch varies with the resistance of that branch. 2. The total current equals the sum of the currents through each branch. 3. The reciprocal of the equivalent resistance equals the sum of the reciprocals of the individual resistances. Which of the statements given above is/are correct?
Adding another finite-resistance branch to an existing parallel combination connected to a fixed-voltage source will:
Assertion (A): In a domestic electric circuit, all appliances are connected in series. Reason (R): In a series circuit, if one component fails, the circuit is broken and none of the components work.
Assertion (A): The cord of an electric heater does not glow while the heating element does. Reason (R): The resistance of the heating element is extremely high compared to that of the cord.
What is the power consumed by an electrical device that draws a current of 0.50 A from a 220 V supply?
Approximately how many electrons constitute a charge of one coulomb?
Which device in a simple DC circuit is primarily used to vary current without altering source voltage?
Which of the following correctly describes the properties of alloys used in electrical heating devices? 1. They readily oxidise at high temperatures. 2. They generally have higher resistivity than pure metals.
At a fixed supply voltage, which resistor will draw the greatest current?
When an additional appliance is connected in parallel across a constant-voltage domestic supply, what happens to the total current drawn from the source?
If the resistance of a conductor connected to a constant voltage source is doubled, the current flowing through it will: