1
JEE Main 2018 (Online) 16th April Morning Slot
+4
-1
A power transmission line feeds input power at 2300 V to a step down transformer with its primary windings having 4000 turns, giving the output power at 230 V. If the current in the primary of the transformer is 5 A, and its efficiency is 90%, the output current would be ;
A
50 A
B
45 A
C
25 A
D
20 A
2
JEE Main 2018 (Online) 16th April Morning Slot
+4
-1
A plane electromagnetic wave of wavelength $$\lambda$$ has an intensity I. It is propagatting along the positive Y-direction. The allowed expressions for the electric and magnetic fields are givn by :
A
B
C
D
3
JEE Main 2018 (Online) 16th April Morning Slot
+4
-1
A coil of cross-sectional area A having n turns is placed in a uniform magnetic field B. When it is rotated with an angular velocity $$\omega ,$$ the maxium e.m.f. induced in the coil will be:
A
3 nBA$$\omega$$
B
$${3 \over 2}$$ nBA$$\omega$$
C
nBA$$\omega$$
D
$${1 \over 2}$$ nBA$$\omega$$
4
JEE Main 2018 (Offline)
+4
-1
In an a.c. circuit, the instantaneous e.m.f. and current are given by
e = 100 sin 30 t
i = 20 sin $$\left( {30t - {\pi \over 4}} \right)$$
In one cycle of a.c., the average power consumed by the circuit and the wattless current are, respectively
A
50, 0
B
50, 10
C
$${{1000} \over {\sqrt 2 }},10$$
D
$${{50} \over {\sqrt 2 }}$$
JEE Main Subjects
Physics
Mechanics
Electricity
Optics
Modern Physics
Chemistry
Physical Chemistry
Inorganic Chemistry
Organic Chemistry
Mathematics
Algebra
Trigonometry
Coordinate Geometry
Calculus
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