1
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$${f_1} + {f_2}$$
2
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
$${20 \over 7}$$
3
AIPMT 2012 Prelims
MCQ (Single Correct Answer)
+4
-1
Change Language
An electron of a stationary hydrogen atom passes from the fifth energy level to the ground level. The velocity that the atom acquired as a result of photon emission will be
A
$${{24hR} \over {25m}}$$
B
$${{25hR} \over {24m}}$$
C
$${{25m} \over {24hR}}$$
D
$${{24m} \over {25hR}}$$
4
AIPMT 2012 Prelims
MCQ (Single Correct Answer)
+4
-1
Change Language
The figure shows a logic circuit with two inputs A and B and the output C. The voltage wave forms across A, B and C are as given. The logic circuit gate is
AIPMT 2012 Prelims Physics - Semiconductor Electronics Question 91 English
A
OR gate
B
NOR gate
C
AND gate
D
NAND gate