1
JEE Main 2017 (Online) 8th April Morning Slot
+4
-1
A magnetic dipole in a constant magnetic field has :
A
maximum potential energy when the torque is maximum.
B
zero potential energy when the torque is minimum.
C
zero potential energy when the torque is maximum.
D
minimum potential energy when the torque is maximum.
2
JEE Main 2017 (Online) 8th April Morning Slot
+4
-1
Magnetic field in a plane electromagnetic wave is given by

$$\overrightarrow B$$ = B0 sin (k x + $$\omega$$t) $$\widehat j\,T$$

Expression for corresponding electric field will be :
Where c is speed of light.
A
$$\overrightarrow E$$ = B0 c sin (k x + $$\omega$$t) $$\widehat k$$ V/m
B
$$\overrightarrow E$$ = $${{{B_0}} \over c}$$ sin (k x + $$\omega$$t) $$\widehat k$$ V/m
C
$$\overrightarrow E$$ = $$-$$ B0 c sin (kx +$$\omega$$t) $$\widehat k$$ V/m
D
$$\overrightarrow E$$ = B0 c sin (kx $$-$$$$\omega$$t) $$\widehat k$$ V/m
3
JEE Main 2017 (Offline)
+4
-1
A magnetic needle of magnetic moment 6.7 $$\times$$ 10-2 A m2 and moment of inertia 7.5 $$\times$$ 10-6 kg m2 is performing simple harmonic oscillations in a magnetic field of 0.01 T. Time taken for 10 complete oscillations is:
A
8.76 s
B
6.65 s
C
8.89 s
D
6.98 s
4
JEE Main 2017 (Offline)
+4
-1
When a current of 5 mA is passed through a galvanometer having a coil of resistance 15$$\Omega$$, it shows full scale deflection. The value of the resistance to be put in series with the galvanometer to convert it into a voltmeter of range 0 – 10V is:
A
4.005 × 103 $$\Omega$$
B
1.985 × 103 $$\Omega$$
C
2.535 × 103 $$\Omega$$
D
2.045 × 103 $$\Omega$$
JEE Main Subjects
Physics
Mechanics
Electricity
Optics
Modern Physics
Chemistry
Physical Chemistry
Inorganic Chemistry
Organic Chemistry
Mathematics
Algebra
Trigonometry
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