1
AIPMT 2012 Prelims
MCQ (Single Correct Answer)
+4
-1
Change Language
Two similar coils of radius R are lying concentrically with their planes at right angles to each other. The currents flowing in them are $$I$$ and 2$$I$$, respectively. The resultant magnetic field induction at the centre will be
A
$${{\sqrt 5 {\mu _0}I} \over {2R}}$$
B
$${{\sqrt 5 {\mu _0}I} \over R}$$
C
$${{{\mu _0}I} \over {2R}}$$
D
$${{{\mu _0}I} \over R}$$
2
AIPMT 2012 Prelims
MCQ (Single Correct Answer)
+4
-1
Change Language
When a biconvex lens of glass having refractive index 1.47 is dipped in a liquid, it acts as a plane sheet of glass. This implies that the liquid must have refractive index
A
equal to that of glass
B
less than one
C
greater than that of glass
D
less than that of glass
3
AIPMT 2012 Prelims
MCQ (Single Correct Answer)
+4
-1
Change Language
A concave mirror of focal length $$f$$1 is placed at a distance of d from a convex lens of focal length $$f$$2. A beam of light coming from infinity and falling on this convex lens $$-$$ concave mirror combination returns to infinity. The distance d must equal
A
$${f_1} + {f_2}$$
B
$$-$$$${f_1} + {f_2}$$
C
2$${f_1} + {f_2}$$
D
$$-$$2$${f_1} + {f_2}$$
4
AIPMT 2012 Prelims
MCQ (Single Correct Answer)
+4
-1
Change Language
Electron in hydrogen atom first jumps from third excited state to second excited state and then from second excited to the first excited state. The ratio of the wavelengths $$\lambda $$1 : $$\lambda $$2 emitted in the two cases is
A
$${7 \over 5}$$
B
$${27 \over 20}$$
C
$${27 \over 5}$$
D
$${20 \over 7}$$