1
MCQ (Single Correct Answer)

JEE Main 2019 (Online) 11th January Evening Slot

A copper wire is wound on a wooden frame, whose shape is that of an equilateral triangle. If the linear dimension of each side of the frame is increased by a factor of 3, keeping the number of turns of the coil per unit length of the frame the same, then the self inductance of the coil:
A
decreases by a factor of $$9\sqrt 3 $$
B
increases by a factor of 27
C
decreases by a factor of 9
D
increases by a factor of 3

Explanation

Total length L will remain constant

L = (3a) N        (N = total turns)

and length of winding = (d) N

                         (d = diameter of wire)


self inductance = $$\mu $$0n2A$$\ell $$

= $$\mu $$0n2$$\left( {{{\sqrt 3 {a^2}} \over 4}} \right)$$ dN

$$ \propto $$ a2 N $$ \propto $$ a

So self inductance will become 3 times
2
MCQ (Single Correct Answer)

JEE Main 2019 (Online) 11th January Evening Slot

Seven capacitors, each of capacitance 2 $$\mu $$F, are to be connected in a configuration to obtain an effective capacitance of $$\left( {{6 \over {13}}} \right)\mu F.$$ Which of the combinations, shown in figures below, will achieve the desired value
A
B
C
D

Explanation

Ceq = $${6 \over {13}}$$$$\mu $$F

Therefore three capacitors most be in parallel to get 6 in

$${1 \over {{C_{eq}}}} = {1 \over {3C}} + {1 \over C} + {1 \over C} + {1 \over C} + {1 \over C}$$

Ceq = $${{3C} \over {13}}$$ = $${6 \over {13}}$$$$\mu $$F

3
MCQ (Single Correct Answer)

JEE Main 2019 (Online) 11th January Evening Slot

In the circuit shown, the potential difference between A and B is :

A
6 V
B
3 V
C
2 V
D
1 V

Explanation

Potential difference across AB will be equal to battery equivalent across CD

VAB $$=$$ VCD $$=$$ $${{{{{E_1}} \over {{r_1}}} + {{{E_2}} \over {{r_2}}} + {{{E_3}} \over {{r_3}}}} \over {{1 \over {{r_1}}} + {1 \over {{r_2}}} + {1 \over {{r_3}}}}} = {{{1 \over 1} + {2 \over 1} + {3 \over 1}} \over {{1 \over 1} + {1 \over 1} + {1 \over 1}}}$$

$$=$$ $${6 \over 3}$$ $$=$$ 2V
4
MCQ (Single Correct Answer)

JEE Main 2019 (Online) 12th January Morning Slot

In the figure shown, after the switch 'S' is turned from position 'A' to position 'B', the energy dissipated in the circuit in terms of capacitance 'C' and total charge 'Q' is :

A
$${1 \over 8}{{{Q^2}} \over C}$$
B
$${5 \over 8}{{{Q^2}} \over C}$$
C
$${3 \over 4}{{{Q^2}} \over C}$$
D
$${3 \over 8}{{{Q^2}} \over C}$$

Explanation

Vi = $${1 \over 2}$$CE2

Vf = $${{{{\left( {CE} \right)}^2}} \over {2 \times 4c}}$$ = $${1 \over 2}{{C{E^2}} \over 4}$$

$$\Delta $$E = $${1 \over 2}$$CE2 $$ \times $$ $${3 \over 4}$$ = $${3 \over 8}$$ CE2

Questions Asked from Current Electricity

On those following papers in MCQ (Single Correct Answer)
Number in Brackets after Paper Name Indicates No of Questions
AIEEE 2002 (6)
keyboard_arrow_right
AIEEE 2003 (6)
keyboard_arrow_right
AIEEE 2004 (10)
keyboard_arrow_right
AIEEE 2005 (7)
keyboard_arrow_right
AIEEE 2006 (5)
keyboard_arrow_right
AIEEE 2007 (2)
keyboard_arrow_right
AIEEE 2008 (4)
keyboard_arrow_right
AIEEE 2010 (2)
keyboard_arrow_right
AIEEE 2011 (1)
keyboard_arrow_right
AIEEE 2012 (1)
keyboard_arrow_right
JEE Main 2013 (Offline) (2)
keyboard_arrow_right
JEE Main 2014 (Offline) (1)
keyboard_arrow_right
JEE Main 2015 (Offline) (2)
keyboard_arrow_right
JEE Main 2016 (Offline) (1)
keyboard_arrow_right
JEE Main 2016 (Online) 9th April Morning Slot (1)
keyboard_arrow_right
JEE Main 2016 (Online) 10th April Morning Slot (1)
keyboard_arrow_right
JEE Main 2017 (Offline) (3)
keyboard_arrow_right
JEE Main 2017 (Online) 8th April Morning Slot (2)
keyboard_arrow_right
JEE Main 2017 (Online) 9th April Morning Slot (3)
keyboard_arrow_right
JEE Main 2018 (Offline) (2)
keyboard_arrow_right
JEE Main 2018 (Online) 15th April Morning Slot (2)
keyboard_arrow_right
JEE Main 2018 (Online) 15th April Evening Slot (2)
keyboard_arrow_right
JEE Main 2018 (Online) 16th April Morning Slot (1)
keyboard_arrow_right
JEE Main 2019 (Online) 9th January Morning Slot (4)
keyboard_arrow_right
JEE Main 2019 (Online) 9th January Evening Slot (3)
keyboard_arrow_right
JEE Main 2019 (Online) 10th January Morning Slot (6)
keyboard_arrow_right
JEE Main 2019 (Online) 10th January Evening Slot (4)
keyboard_arrow_right
JEE Main 2019 (Online) 11th January Morning Slot (5)
keyboard_arrow_right
JEE Main 2019 (Online) 11th January Evening Slot (5)
keyboard_arrow_right
JEE Main 2019 (Online) 12th January Morning Slot (5)
keyboard_arrow_right
JEE Main 2019 (Online) 12th January Evening Slot (5)
keyboard_arrow_right
JEE Main 2019 (Online) 8th April Morning Slot (6)
keyboard_arrow_right
JEE Main 2019 (Online) 8th April Evening Slot (4)
keyboard_arrow_right
JEE Main 2019 (Online) 9th April Morning Slot (3)
keyboard_arrow_right
JEE Main 2019 (Online) 9th April Evening Slot (4)
keyboard_arrow_right
JEE Main 2019 (Online) 10th April Morning Slot (5)
keyboard_arrow_right
JEE Main 2019 (Online) 10th April Evening Slot (2)
keyboard_arrow_right
JEE Main 2019 (Online) 12th April Morning Slot (5)
keyboard_arrow_right
JEE Main 2019 (Online) 12th April Evening Slot (3)
keyboard_arrow_right
JEE Main 2020 (Online) 7th January Morning Slot (1)
keyboard_arrow_right
JEE Main 2020 (Online) 7th January Evening Slot (3)
keyboard_arrow_right
JEE Main 2020 (Online) 8th January Morning Slot (1)
keyboard_arrow_right
JEE Main 2020 (Online) 8th January Evening Slot (4)
keyboard_arrow_right
JEE Main 2020 (Online) 9th January Morning Slot (1)
keyboard_arrow_right
JEE Main 2020 (Online) 9th January Evening Slot (3)
keyboard_arrow_right
JEE Main 2020 (Online) 4th September Morning Slot (2)
keyboard_arrow_right
JEE Main 2020 (Online) 2nd September Morning Slot (2)
keyboard_arrow_right
JEE Main 2020 (Online) 2nd September Evening Slot (4)
keyboard_arrow_right
JEE Main 2020 (Online) 3rd September Morning Slot (3)
keyboard_arrow_right
JEE Main 2020 (Online) 3rd September Evening Slot (2)
keyboard_arrow_right
JEE Main 2020 (Online) 4th September Evening Slot (3)
keyboard_arrow_right
JEE Main 2020 (Online) 5th September Morning Slot (4)
keyboard_arrow_right
JEE Main 2020 (Online) 5th September Evening Slot (3)
keyboard_arrow_right
JEE Main 2020 (Online) 6th September Morning Slot (1)
keyboard_arrow_right
JEE Main 2020 (Online) 6th September Evening Slot (4)
keyboard_arrow_right
JEE Main 2021 (Online) 24th February Morning Slot (3)
keyboard_arrow_right
JEE Main 2021 (Online) 25th February Evening Shift (2)
keyboard_arrow_right
JEE Main 2021 (Online) 26th February Morning Shift (3)
keyboard_arrow_right
JEE Main 2021 (Online) 26th February Evening Shift (3)
keyboard_arrow_right
JEE Main 2021 (Online) 16th March Morning Shift (1)
keyboard_arrow_right
JEE Main 2021 (Online) 16th March Evening Shift (1)
keyboard_arrow_right
JEE Main 2021 (Online) 17th March Evening Shift (2)
keyboard_arrow_right
JEE Main 2021 (Online) 18th March Morning Shift (1)
keyboard_arrow_right
JEE Main 2021 (Online) 20th July Morning Shift (2)
keyboard_arrow_right
JEE Main 2021 (Online) 25th July Morning Shift (2)
keyboard_arrow_right
JEE Main 2021 (Online) 25th July Evening Shift (3)
keyboard_arrow_right
JEE Main 2021 (Online) 27th July Morning Shift (4)
keyboard_arrow_right
JEE Main 2021 (Online) 27th July Evening Shift (2)
keyboard_arrow_right
JEE Main 2021 (Online) 26th August Morning Shift (3)
keyboard_arrow_right
JEE Main 2021 (Online) 26th August Evening Shift (3)
keyboard_arrow_right
JEE Main 2021 (Online) 27th August Morning Shift (3)
keyboard_arrow_right
JEE Main 2021 (Online) 27th August Evening Shift (2)
keyboard_arrow_right
JEE Main 2021 (Online) 31st August Morning Shift (1)
keyboard_arrow_right

EXAM MAP

Joint Entrance Examination

JEE Advanced JEE Main

Graduate Aptitude Test in Engineering

GATE CSE GATE ECE GATE ME GATE PI GATE EE GATE CE GATE IN

Medical

NEET