1
AIPMT 2007
MCQ (Single Correct Answer)
+4
-1
Charges +q and $$-$$q are placed at points A and B respectively which are a distance 2L apart, C is the midnight between A and B. The work done in moving a charge + Q along the semicircle CRD is

AIPMT 2007 Physics - Electrostatics Question 44 English
A
$${{qQ} \over {2\pi {\varepsilon _0}L}}$$
B
$${{qQ} \over {6\pi {\varepsilon _0}L}}$$
C
$$-$$ $${{qQ} \over {6\pi {\varepsilon _0}L}}$$
D
$${{qQ} \over {4\pi {\varepsilon _0}L}}$$
2
AIPMT 2007
MCQ (Single Correct Answer)
+4
-1
For a cubic crystal structure which one of the following relations indicating the cell characteristics is correct ?
A
a $$ \ne $$ b $$ \ne $$ c  and  $$\alpha $$ = $$\beta $$ = $$\gamma $$ = 90o
B
a = b = c  and  $$\alpha $$ $$ \ne $$ $$\beta $$ $$ \ne $$ $$\gamma $$ = 90o
C
a = b = c  and  $$\alpha $$ = $$\beta $$ = $$\gamma $$ = 90o
D
a $$ \ne $$ b $$ \ne $$ c  and  ;$$\alpha $$ $$ \ne $$ $$\beta $$ $$ \ne $$  and  $$\gamma $$ = 90o
3
AIPMT 2007
MCQ (Single Correct Answer)
+4
-1
Which one of the following represents forward bias diode ?
A
AIPMT 2007 Physics - Semiconductor Electronics Question 114 English Option 1
B
AIPMT 2007 Physics - Semiconductor Electronics Question 114 English Option 2
C
AIPMT 2007 Physics - Semiconductor Electronics Question 114 English Option 3
D
AIPMT 2007 Physics - Semiconductor Electronics Question 114 English Option 4
4
AIPMT 2007
MCQ (Single Correct Answer)
+4
-1
In a mass spectrometer used for measuring the masses of ions, the ions are initially accelerated by an electric potential $$V$$ and then made to describe semicircular paths of radius R using a magnetic field B. If V and B are kept constant, the ratio $$\left( {{{ch\arg e\,\,on\,\,\,the\,\,ion\,\,} \over {mass\,\,of\,\,the\,\,ion}}} \right)$$ will be proportional to
A
1/R2
B
R2
C
R
D
1/R