1
NEET 2016 Phase 2
MCQ (Single Correct Answer)
+4
-1
Change Language
A filament bulb (500 W, 100 V) is to be used in a 230 V main supply. When a resistance R is connected in series, it works perfectly and the bulb consumes 500 W. The value of R is
A
230 $$\Omega $$
B
46 $$\Omega $$
C
26 $$\Omega $$
D
13 $$\Omega $$
2
NEET 2016 Phase 2
MCQ (Single Correct Answer)
+4
-1
Change Language
A long wire carrying a steady current is bent into a circular loop of one turn. The magnetic field at the centre of the loop is B. It is then bent into a circular coil of n turns. The magnetic field at the centre of this coil of n turns will be
A
nB
B
n2B
C
2nB
D
2n2B
3
NEET 2016 Phase 2
MCQ (Single Correct Answer)
+4
-1
Change Language
An electron is moving in a circular path under the influence of a transverse magnetic field of 3.57 $$ \times $$ 10-2 T. If the value of e/m is 1.76 $$ \times $$ 1011 C kg$$-$$1, the frequency of revoluation of the electron is
A
1 GHz
B
100 MHz
C
62.8 MHz
D
6.28 MHz
4
NEET 2016 Phase 2
MCQ (Single Correct Answer)
+4
-1
Change Language
A bar magnet is hung by a thin cotton thread in a uniform horizontal magnetic field and is in equilibrium state. The energy required to rotate it by 60o is W. Now the torque required to keep the magnet in this new position is
A
$${W \over {\sqrt 3 }}$$
B
$$\sqrt 3 W$$
C
$${{\sqrt 3 W} \over 2}$$
D
$${{2W} \over {\sqrt 3 }}$$
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