Physics 10

Analyze IV characteristic graphs for a metallic conductor, an incandescent bulb, and a thermistor to determine ohmic and non-ohmic behavior.

Analysis of IV Characteristic Graphs for Different Conductors The I-V characteristic graph represents the relationship between the current (I) and voltage (V) for different electrical components. The nature of this graph helps determine whether a material exhibits Ohmic or Non-Ohmic behavior.  1. Metallic Conductor (Ohmic Behavior) Graph Shape: A straight line passing through the origin. … Read more

Explain Ohm’s Law. What are its limitations? Differentiate between ohmic and non-ohmic conductors.

Ohm’s Law Ohm’s Law states that the current (III) flowing through a conductor is directly proportional to the voltage (VVV) across it, provided the temperature and other physical conditions remain constant. Mathematically, it is expressed as: V=IR where: V = Voltage (Volts, V) I = Current (Amperes, A) R = Resistance (Ohms, Ω\OmegaΩ) Limitations of Ohm’s … Read more

How can you differentiate between emf and potential difference? What do you mean by emf? Is it really a force? Explain

Difference Between EMF and Potential Difference Aspect Electromotive Force (EMF) Potential Difference (PD) Definition The total energy supplied by a source per unit charge to drive the charge around a complete circuit. The energy difference per unit charge between two points in a circuit. Symbol ε V Formula ε= W/Q​ V=W/Q​ Source Produced by a … Read more

Define and explain the term electric current. What is the difference between electronic current and conventional current?

Definition of Electric Current Electric current (III) is defined as the rate of flow of electric charge through a conductor or circuit. Mathematically, it is expressed as: I=Q/t​ where: I = current (in amperes, A Q = charge (in coulombs, C) t = time (in seconds, s) The SI unit of electric current is the … Read more

Show that Volt-Ampere is equal to Watt (SI unit of power).

To show that Volt-Ampere (VA) is equal to Watt (W), let’s analyze the units step by step. Step 1: Define Power Electrical power (P) is given by: P=V×I where: V is the voltage in volts (V), I is the current in amperes (A). Step 2: Express SI Units The SI unit of voltage (V) is: 1 … Read more

One of a car’s headlamps is burnt, but the second lamp is still working. What does this indicate about the connection?

This indicates that the headlamps are connected in parallel. In a series circuit, if one bulb burns out, the entire circuit breaks, and both lamps stop working. In a parallel circuit, each lamp has an independent path to the power source. If one burns out, the other continues working normally. This is why automobile headlights … Read more

Why is it dangerous to touch a live wire while standing barefoot on the earth?

The earth acts as a conductor and is considered to be at zero potential. If a person touches a live wire while barefoot, a potential difference is created between the body and the earth, allowing current to flow through the body to the ground. This can result in severe electric shock or electrocution. To prevent … Read more

Why are we advised not to touch electrical switches with wet hands?

Water is a good conductor of electricity, especially when mixed with impurities. When hands are wet: The skin’s resistance decreases. A larger current can pass through the body if contact is made with a live wire. This can cause electric shock or serious injury. Dry hands have higher resistance, reducing the risk of electric shock. … Read more

Two electric bulbs marked 100 W, 220 V and 200 W, 220 V have tungsten filaments of the same length. Which bulb has a thicker filament?

The resistance of a filament is given by Ohm’s law: R=V2/P​ where: V=220V (same for both bulbs), P is the power rating. Step 1: Calculate the Resistance of Each Bulb For the 100 W bulb: R1=2202/100=48400/100=484 Ω For the 200 W bulb: R2=2202/200=48400/200=242 Ω Step 2: Relationship Between Resistance and Thickness The resistance of a wire is … Read more

6. You are given wires, each with resistance . What is the ratio of maximum to minimum resistance that can be obtained?

To solve this problem, we need to understand how the resistance behaves when wires are combined in series or parallel. Maximum Resistance: When resistances are combined in series, the total resistance is the sum of the individual resistances. For n wires, each with resistance R, the total resistance in series is: Rtotal series=nR So, the maximum … Read more