unacademy 432 vics Plz follow Rate Review & LIKE Rahul Rishi Educator snce September 2018 GOLD MEDALIST 'in PHYSICS, CSIR NET qualified you tuber, Passionate reader and Teacher for lIT JEE NEET, IIT JAMadsir Nel plryesins 54 53 Flomna Fakng Cues Follow All courses (3) HINDI Physics Previous Year Question (Hindi) Super Duper Tricks in Physics: NEET, IIT JEE Students (ratings) Rahu Rishi unacademy
Problem 1 Charge Q divided into two parts which are then kept some distance apart. The force between them will be maximum if the two parts are (a) Q/2 each (b) Q/4 and 3Q/4 (c) e and (Q-e), where e-electronic charge Tips:- For F to be maximum dF - o =0 dq 9 (0-4) d2 solving Force b/w them F = 2 q= 2
Problem2- Two identical metal balls with charges +2Q andQare separated by some distance, and exert a force F on each other, they are joined by a conducting wire which is then removed. The force between them will now be (a) F (b) F2 (c)F/4 (d) F/8 Tips: 2Q2 F = k , where d = separation. d2 since charge is shared , the charge on each ball (20-Q) =- 2 The force now becomes F' = k (q/212-1 d2 4 d28
Problem 3-1A capacitor is connected to a cell of emf E and some internal resistance The potential difference across the (a) Cell is E (b) Cell is E (c) Capacitor is <E (d) Capacitor is >E When a capacitor is fully charged, it draws no current. when no current flows in the circuit, potential difference across the cell emf of cell potential difference across the capacitor. Tips
Problem 4 A simple pendulum of time period T is suspended above a large horizontal metal sheet with uniformly distributed positive charge. If the bob is given some negative charges, its time period of oscillation will be a) >T (b) <T (c) T (a) proportional to its amplitude The metal sheet produces a uniform T PGJ. upward electric field, causing a constant downward force on the bob in all positions. This increases the effective value of g, reducing T. mg + qE Where Trick T- 2L eff
Problem5t In the network shown below, the equivalent resistance between A and B is (a) R/2 (b) R (c) 2R (d)4R Tipsi Any circuit element situated between points at the same potential can be removed from the circuit. By symmentry, points A and B are the same potential. Thus, removing the resistances of 2R, 2R and R in parallel. 2
"GOLD MEDALIST "in PHYSICS. CSIR NET qualified ..you tuber , Passionate reader and Teacher for IIT JEE ,NEET, IIT JAM and csir Net physics.