NCERT MCQ Solutions for Class 10 Science Chapter 11 Electricity

Electric current is measured in amperes. One ampere equals one coulomb of charge passing through a point in a circuit per second. It is the standard SI unit used in all electric current measurements and circuit calculations.

One volt is defined as the work of one joule done to move one coulomb of charge between two points in an electric field. Hence voltage represents energy per unit charge.

Ohm’s law establishes a direct proportionality between voltage and current when resistance remains constant. It is a fundamental principle used in analyzing electric circuits and determining unknown values.

Resistance increases proportionally with length. When the length of a conductor doubles and other factors like material and cross-sectional area remain constant its resistance also doubles.

Resistance decreases as the cross-sectional area increases. This is because a wider path allows more electrons to flow freely reducing the overall resistance in the conductor.

Electrical power is the rate at which energy is consumed. It is calculated by multiplying voltage and current and the unit of power is watt which equals one joule per second.

Fuse wires are made of materials with relatively high resistance and low melting point so they melt quickly when excessive current flows and protect electrical devices.

Resistivity quantifies how strongly a material opposes the flow of current. It depends only on the material and is expressed in ohm meters. It remains constant for a given material.

Using the formula R = V²/P = 220²/100 we get resistance as 484 ohms. It tells us how much the bulb resists the flow of current when operated at its rated values.

Copper has low resistivity and high conductivity. It allows electric current to pass through easily making it ideal for electrical wiring and other conductive applications.

Charge is measured in coulombs. One coulomb is defined as the amount of charge transferred by a current of one ampere in one second through a conductor.

Potential difference represents the work done to move a unit charge from one point to another in an electric field. It is measured in volts and determines energy per charge.

An ammeter is connected in series in a circuit to measure current. It has low internal resistance to ensure accurate readings without altering the current significantly.

In a series circuit the current remains constant while the voltage is divided among the resistors proportionally according to their resistance values. The total resistance adds up.

In a parallel connection the voltage across all resistors is the same but the total current is distributed among them. The inverse of total resistance equals the sum of reciprocals.

A fuse is a safety device that breaks the circuit by melting when current exceeds a certain limit. It prevents damage from overheating short circuits or overloads.

One kilowatt hour is equal to 1000 watts of power used for 3600 seconds. Multiplying gives 3.6 million joules which is the energy consumed by electrical devices.

In parallel combination the effective resistance is always less than the smallest individual resistor. This setup offers multiple paths for current reducing overall resistance.

Electric energy consumed is calculated by multiplying the power used with the time it is operated. The result is expressed in watt-hours or joules depending on the context.

Resistance is directly proportional to length and inversely proportional to cross-sectional area. It also depends on the material’s resistivity which is a constant for each material.