Physics : Tips & Tricks

How to Solve any Physics Problem : Additional Critical Tips :
 * 1) Draw a Rough Diagram
 * 2) List down the knowns and unknowns
 * 3) Use the best Equation
 * 4) Solve it Symbolically
 * 5) Arrive on an Answer
 * 1) For Graphs, use only formulae . Substitute different values to obtain the graph.
 * 2) In case of questions on force or components ; look for al the important forces/components.
 * 3) If all particles of a body are contributing to a quantity, e.g. Moment of Inertia , Gravitational Field , Electric Field , Magnetic Field ; then find the quantity for a small elemental area and then integrate it between appropriate limits.

Measurements

 * 1) Use dimensional analysis to eliminate options . Try to match dimensions.

Scalars and Vectors
1) If in any question, based on any chapter , direction is being asked , then always work with vectors (xi + yj + zk)

Kinematics

 * 1) Preferably make use of Kinematical Equations only.
 * 2) For 2 dimensiional and three dimensiona motion, break down the motion into 2/3 components and apply kinematic equations to ach independently . (e.g. Projectile Motion )

Force
1) Working with Newton's Laws of Motion

i. Select the system

ii. Identify the forces

iii. Make a free body diagram

iv. Choose and write Equations

2) Working with Tension in String :

Work, Energy and Power
The concepts of Work and Energy can be applied to all MCQs, dealing with momentum , force , velocity , acceleration and height.

Friction in Solids and Fluids

 * 1) For friction, draw the free body diagram and resolve the vectors . Mostly , the free body diagram is standard , so you can learn the resolved forces beforehand.

Rotational Motion

 * 1) For a system of bodies, add up their individual moments of inertia.

Electrostatics
1) For repulsive force between two like charges, the closest distance of approach is when Kinetic Energy is equal to Potential Energy.

2) For questions related to Flux and Electric Field Intensity, consider Gauss Theorem .

3) The formulae for E, at diffrent distances from a conductor , circular conductor and at centre of circular conductor is the same as B.

Current Electricity

 * 1) For solving resistances in series and parallel, draw a simpler equivalent diagram of circuit.
 * 2) When n resistors of Resistance R are connected in series, the total resistance is nR.
 * 3) When n series of Resistance R are connected in parallel, the total resistance is R/n.
 * 4) If a wire of resistance R is stretched n (l2/l1) times, The new resistance is n2R
 * 5) When a complicated symmetric circuit is given for finding resistance, it can be divided into halves to simplify the circuit.
 * 6) When simplifying a circuit, plot points on the circuit to guide you.
 * 7) In Wheatstone's network, if the network is balanced , the middle resistance is ignored because no current flows through it.
 * 8) Whenever, a part of circuit confuses you , remove it and see it's role in the circuit.
 * 9) The effective resistance for a balanced Wheatstone's Network is R
 * 10) For equivalent resistances, consider current through each branch.
 * 11) Use Kirchoff's laws for complicated circuits.