A thermocouple of negligible resistance
produces an e.m.f. of 40 µV/ºC in the linear range
of temperature. A galvanometer of resistance 10
ohm whose sensitivity is 1 µA/division, is
employed with the thermocouple. The smallest
value of temperature difference that can be
detected by the system will be
A
1ºC
B
0.5 ºC
C
0.1ºC
D
0.25ºC
2
AIPMT 2011 Mains
MCQ (Single Correct Answer)
+4
-1
Charge q is uniformly spread on a thin ring of radius R. The ring rotates about its axis with a uniform frequency $$f$$ Hz. The magnitude of magnetic induction at the center of the ring is
A
$${{{\mu _0}qf} \over {2\pi R}}$$
B
$${{{\mu _0}qf} \over {2R}}$$
C
$${{{\mu _0}q} \over {2fR}}$$
D
$${{{\mu _0}q} \over {2\pi fR}}$$
3
AIPMT 2011 Mains
MCQ (Single Correct Answer)
+4
-1
Pure Si at 500 K has equal number of electron (ne) and hole (nh) concentrations of 1.5 $$ \times $$ 1016 m$$-$$3. Doping by indium increases nh to 4.5 $$ \times $$ 1022 m$$-$$3. The doped semiconductor is of
A
p-type having electron concentration ne = 5 $$ \times $$ 109 m$$-$$3
B
n-type with electron concentration ne = 5 $$ \times $$ 1022 m$$-$$3
C
p-type with electron concentration ne = 2.5 $$ \times $$ 1010 m$$-$$3
D
n-type with electron concentration ne = 2.5 $$ \times $$ 1023 m$$-$$3
4
AIPMT 2011 Mains
MCQ (Single Correct Answer)
+4
-1
In the following figure, the diodes which are forward biased, are
