How to Prepare Current Electricity for NSEP

Updated on 07 Nov 2022, 03:38 PM IST

National Standard Examination In Physics (NSEP) is conducted every year by the Indian Association Of Physics Teachers (IAPT). Toppers of NSEP can attend Indian National Physics Olympiad (INPhO). To qualify for an exam like NSEP it is important to know every topic in the syllabus and the type of questions asked in the NSEP previous year question papers. Here we discuss the tips for how to prepare Current Electricity for NSEP

How To Prepare Current Electricity For NSEP(Image: Shutterstock)

NSEP Syllabus For Current Electricity includes, Concepts of Electric Current, Drift Velocity, Mobility, resistance, Resistivity, Conductivity, Ohm's law, Colour Coding of Resistance, The Combination of Resistance, Cells and Combination, Electrical Energy and Power, Kirchoff's laws, Whetstones Bridge, Meter Bridge and Potentiometer.

Tips To Prepare Current Electricity For NSEP

Study all the concepts of NCERT book Class 12 Physics chapter Current Electricity.
Solve questions from NCERT book and NCERT exemplar.
Solve more circuit problems related to the combination of resistance and cells.
Understand how to apply Kirchoff's laws in circuits.
Solve questions based on whetstones bridge, meter bridge and potentiometer

Current Electricity Important Formulas

Drift Velocity(vd)

E- Electric Field

T- Relaxation time

E-charge of the electron

m - the mass of the electron

Resistance

$R=\rho\frac{l}{A}$

⍴-resistivity

l and A are the length and area of the conductor

Resistivity

Current Division Rule

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Combination Of Cells

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$i=\frac{nE}{R+nr}$

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Potentiometer Application

Comparison of emf:

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$\frac{E_{1}}{E_{2}}=\frac{l_{1}}{l_{2}}$

To determine the internal resistance of a cell:

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$r=(\frac{l_{1}-l_{2}}{l_{2}})R$

$r=(\frac{E}{V}-1)R$

Wheatstone's Bridge

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Balance Condition-

$\frac{P}{Q}= \frac{R}{S}$

$V_{B} = V_{D}$

Meter Bridge

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$\frac{P}{Q}=\frac{R}{S}\Rightarrow S= \frac{(100-l)}{l}R$

NSEP Previous Year Questions

Q-1- Two cells each of emf E and internal resistances r1 and r2 respectively are connected in series with an external resistance R. The potential difference between the terminals of the first cell will be zero when R is equal to(NSEP 2017)

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Q-2- In the circuit shown R1 not equal to R2. The reading in the galvanometer is the same with switch S open or closed. Then(NSEP 2018)

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(a) I1 = IG (b) I2 = IG (c) I3 = IG (d) I4 = IG

Q-3- The effective resistance between points A and B in the circuit arrangement shown below is(NSEP 2018)

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(a) 14 Ω. (b) 15 Ω. (c) 30 Ω. (d) none of the above.

Q-4- In the circuit arrangement shown two cells supply a current I to a load resistance R = 9 Ω. One cell has an emf E1 = 9 V and internal resistance r1 = 1 Ω and the other cell has an emf E2 = 6 V and internal resistance r2 = 3 Ω. The currents are as shown. Then, (NSEP 2018- Morethan one option correct)

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(a) I1 = 0.9 A and I2 = 0.5 A.

(b) I 0.85 A.

(d) if the cell of emf E2 is removed, current I will be smaller.

Q-5-

If a cell of constant emf produces the same amount of heat during the same time in two independent resistors R1 and R2 when they are separately connected across the terminals of the cell, one after the other. The internal resistance of the cell is(NSEP 2019)

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Q-6- Identify the rank in order from the dimmest to the brightest when all the identical bulbs are connected in the circuit as shown below.

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(a) A= B > C = D (b) A= B = C = D (c) A> C > B > D (d) A= B < C = D

Q-7- In the circuit shown if an ideal ammeter is connected between A and B then the direction of current and the current reading would be (assume I remains unchanged) (NSEP 2019)

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