PHY301 Final Term Past Papers Set 3 by VUBuddy

PHY301-Circuit Theory lecture wise Question& Answers Prepared By

Explain KCL equations?

KCL equation is written in nodal analysis to write nodal equation. To write KCL, we make use of Ohm’s law in the form of I=V/R

At node (1)

V1/3k +4mA +2mA + (V1-V2) /6k =0

To simplify this equation, we take L.C.M. 6 and multiply each term by 6 on both sides. So

6xV1/3k +6x 4mA +6x 2mA + 6x (V1-V2) /6k =6x 0 Solving this we get

2V1 +24 +12 +V1 – V2 =0 3V1 –V2 = -36

At node (2)

V2/4k + V2/12k - 2mA +(V2 –V1)/6k = 0

To simplify this equation, we take L.C.M. 12 and multiply each term by 12 on both sides. So

12xV2/4k + 12x V2/12k - 12x 2mA +12x (V2 –V1)/6k = 0 Solving this we get

3V2 +V2– 24 + 2V2 – 2V1 = 0 6V2 – 2V1 = 24 Q)isMATRICES AND DETERMINANTS to solve the KCL and KVL equations is an easy and short method? Matrices and determinant method is another technique used to solve simultaneously equations having different variables. However, you can use any convenient and simple method to solve such equations. It’s on your choice.

Linear circuit

Linear circuits are proportional circuits having the output directly related to the input. In a linear circuit if we plot the Input vs Output of a circuit, it will be a straight line.

For example if we increase the value of applied voltage across a linear circuit, the current flowing in the circuit will increase proportional to the applied voltage.

Superposition Theorem

Dear Student, The Superposition Theorem is an important concept in circuit analysis. It allows you to determine a voltage across a component or a branch current by calculating the effect of each source individually, and then algebraically adding each contribution. Superposition may be considered for circuit analysis when: There are two or more energy sources. The sources are either voltage or current sources. The circuit is not too complex. There are five steps used in applying the Superposition theorem to a circuit.

1. Select one energy source.
2. Remove all other sources by

• Replacing voltage sources with a short while retaining any internal source resistance.
• Replacing current sources with an open while retaining any internal resistances.

3. Calculate the desired voltage drops or branch currents paying attention to the voltage polarities and current directions.
4. Repeat steps 1 through 3 for each other source individually.
5. Algebraically add the contributions of each voltage or current.

Source transformation

In a circuit containing dependent and independent sources, transformation is usually done by independent current or voltage sources keeping the dependent source constant.

What is simulation package?

Simulation software is computer model based on the process of modeling a real or proposed system with a set of mathematical formulas. It is, essentially, a program that allows the user to do an operation through simulation without actually performing that operation. The simulation is time based, and takes into account all the resources and constraints involved, as well as the way these things interact with each other as time passes. Simulation also builds in the randomness you would see in real life. Simulation software is used widely to design equipment so that the final product will be as close to design specs as possible without expensive in process modification. Simulation software with real-time response is often used in gaming, but it also has important industrial applications. When the penalty for improper operation is costly, such as airplane pilots, nuclear power plant operators, or chemical plant operators, a mock up of the actual control panel is connected to a real-time simulation of the physical response, giving valuable training experience without fear of a disastrous outcome.