Dimensional analysis is a problem-solving technique commonly used in physics and other sciences to analyze and solve problems related to units of measurement. It involves examining the dimensions (units) of physical quantities and using their relationships to derive meaningful equations or verify the correctness of equations.
In dimensional analysis, quantities are expressed in terms of fundamental dimensions such as length, mass, time, and electric charge. Each physical quantity is assigned a dimensional formula that represents its units in terms of these fundamental dimensions.
The steps involved in solving dimensional analysis questions are as follows:

1. Identify the given quantities and the desired quantity: Determine the physical quantities involved in the problem and the quantity you are trying to find.
2. List the dimensions of each quantity: Write down the dimensional formula for each quantity involved, using the fundamental dimensions. For example, the dimensional formula for velocity is [L][T]^-1, where [L] represents length and [T] represents time.
3. Analyze the equation or relationship: Examine the relationship between the given quantities and the desired quantity. Determine how the dimensions of the given quantities are related to the dimensions of the desired quantity.
4. Set up and manipulate equations: Use the dimensional formulas to set up equations that equate the dimensions of the given quantities to the dimensions of the desired quantity. Manipulate the equations algebraically to isolate the desired quantity.
5. Check units and cancel out dimensions: Substitute the units of the given quantities into the equations and ensure that the dimensions on both sides of the equation are consistent. Cancel out matching dimensions to simplify the equation and obtain the desired quantity.
6. Solve the equation and interpret the result: Solve the equation to obtain the numerical value of the desired quantity. Make sure to include the appropriate units based on the dimensional analysis.

Dimensional analysis allows you to check the validity of equations, convert between different units, and derive relationships between physical quantities without performing detailed calculations. It helps ensure that equations are dimensionally consistent and provides a systematic approach to problem-solving in physics.