If you’re a 12th class student studying physics under the Lahore board, then you’ve come to the right place! In this blog article, we will be addressing the important practical question for the year 2018. Instead of beating around the bush, let’s dive straight into it. Have you been wondering about the crucial practical question for the physics 12th class Lahore board exam in 2018? Well, the wait is over! We have the solution you need, and we’re going to discuss it in detail in this article. So, let’s not waste any more time and get started!

## Physics 12th Class Lahore Board Important Practical Question 2018

Physics is a captivating and fundamental branch of science that seeks to explain the behavior of matter and energy in the universe. For students of Class 12 studying under the Lahore Board, it is crucial to have a strong understanding of the subject’s practical aspects. In this article, we will delve into the important practical questions from the Physics syllabus of the Lahore Board for the year 2018.

### Pendulum Experiment

One of the essential practical experiments in 12th-grade Physics is the Pendulum experiment. This experiment focuses on understanding the motion and time period of a simple pendulum. Here are a few important questions related to this experiment:

1. What factors affect the time period of a pendulum?

– Length of the pendulum

– Mass of the bob

– Amplitude of the swing

2. How can the time period of a pendulum be determined?

The time period can be calculated using the formula:

T = 2π√(L/g)

Where T is the time period, L is the length of the pendulum, and g is the acceleration due to gravity.

3. How can the error in the calculated time period be minimized?

– Ensure the pendulum swings in a small amplitude (less than 10 degrees).

– Use a stopwatch with high precision.

– Take multiple measurements and calculate the average time period.

### Measurement of Resistivity

The measurement of resistivity is another important practical experiment in physics. It involves determining the resistivity of a given wire using the four-probe method. Here are some key questions related to this experiment:

1. What is resistivity, and how is it different from resistance?

– Resistance is the property of a conductor to resist the flow of electric current, measured in ohms.

– Resistivity, denoted by the Greek letter ρ (rho), is the intrinsic property of a material to oppose electric current flow per unit length, measured in ohm-meters.

2. How is the resistivity of a wire measured using the four-probe method?

– Connect four probes to the wire: two for current input and two for voltage measurement.

– Apply a known current through the wire and measure the voltage drop across the length of the wire.

– Use the formula: Resistivity (ρ) = (V × A) / (I × l)

– Where V is the voltage measured, A is the cross-sectional area of the wire, I is the current applied, and l is the length of the wire between the probes.

3. How can the accuracy of resistivity measurements be improved?

– Use thicker wires to reduce heating effects.

– Ensure proper contacts between the probes and the wire.

– Take multiple readings and calculate the average resistivity.

### Determination of Focal Length of a Convex Lens

The experiment to determine the focal length of a convex lens is significant in understanding the behavior of light rays passing through a lens. Here are some important questions related to this experiment:

1. How can the focal length of a convex lens be determined?

– Set up the experiment using a lens, a screen, and an object.

– Adjust the distance between the object and the lens until a sharp image appears on the screen.

– Measure the object distance (u) and the image distance (v).

– Use the lens formula: 1/f = 1/v – 1/u, where f is the focal length.

2. What factors can affect the accuracy of the focal length measurement?

– Ensure the object distance is significantly larger than the focal length.

– Measure the distances accurately using a ruler or vernier caliper.

– Minimize parallax error by aligning the object, lens, and screen properly.

3. What are the applications of knowing the focal length of a lens?

– Designing optical instruments like cameras, telescopes, and microscopes.

– Correcting vision problems using eyeglasses and contact lenses.

– Understanding the formation of images in the human eye.

### Measurement of Specific Heat Capacity

The measurement of specific heat capacity is an important practical experiment that involves determining the amount of heat absorbed or released by a substance. Here are some key questions related to this experiment:

1. What is specific heat capacity?

– Specific heat capacity is the amount of heat energy required to raise the temperature of a unit mass of a substance by one degree Celsius (or Kelvin).

2. How can the specific heat capacity of a substance be measured?

– Set up the experiment using a calorimeter, a heater, and a thermometer.

– Heat a known mass of the substance using the heater.

– Measure the initial and final temperatures, and the amount of heat supplied.

– Use the formula: Specific heat capacity (c) = Q / (m × ΔT),

where Q is the heat supplied, m is the mass, and ΔT is the change in temperature.

3. What precautions should be taken during the experiment?

– Use a stirrer to ensure uniform heating of the substance.

– Minimize heat loss to the surroundings by insulating the calorimeter.

– Use a sensitive and calibrated thermometer for accurate temperature measurements.

These are just a few examples of the important practical questions from the Physics syllabus of the 12th Class Lahore Board in 2018. It is crucial for students to thoroughly understand these experiments and their underlying concepts to excel in their examinations. Practice and experimentation are essential for mastering the practical aspects of Physics. Implementing these experiments in the laboratory and seeking guidance from teachers can further enhance understanding and clarity.

### 2nd year physics practical 2023 ||class 12 physics practical 2023 ||physics practical class 12

## Frequently Asked Questions

### What are some important practical questions for the Physics 12th class Lahore Board in 2018?

Here are some important practical questions for the Physics 12th class Lahore Board in 2018:

### How can we determine the focal length of a convex lens using a convex lens formula?

To determine the focal length of a convex lens using a convex lens formula, one can place an object beyond the 2F point of the lens. By measuring the object distance (u) and the image distance (v) using a ruler, and substituting these values into the lens formula (1/f = 1/v – 1/u), the focal length (f) can be calculated.

### What is the procedure for determining the resistance of a given wire using a meter bridge?

The resistance of a given wire can be determined using a meter bridge by following these steps:

1. Connect the resistance wire to the meter bridge circuit.

2. Adjust the jockey’s position until the null point is achieved (the galvanometer shows zero deflection).

3. Measure the length (l) of the resistance wire between the jockey and the end, as well as the length (L) of the meter wire.

4. Calculate the unknown resistance (R) using the formula R = (l/L) * known resistance.

### How can one experimentally verify Ohm’s law using a circuit setup?

To experimentally verify Ohm’s law using a circuit setup, follow these steps:

1. Construct a simple circuit with a power supply, an ammeter, and a resistor.

2. Measure the current (I) flowing through the circuit using the ammeter.

3. Measure the voltage (V) across the resistor using a voltmeter.

4. Repeat the measurements for different values of current and voltage.

5. Plot a graph with voltage on the x-axis and current on the y-axis.

6. If the graph is a straight line passing through the origin, it confirms that the circuit obeys Ohm’s law (V = IR).

## Final Thoughts

In conclusion, the Physics 12th class Lahore Board important practical question 2018 is a valuable resource for students preparing for their examinations. This set of questions covers a wide range of topics and helps students enhance their understanding of key concepts in physics. By practicing these questions, students can develop their problem-solving skills and gain confidence in their abilities. With a focus on active learning, these practical questions provide a hands-on approach to mastering the subject. Overall, the Physics 12th class Lahore Board important practical question 2018 is an essential tool for students aiming to excel in their physics exams.