IIT-JEE 2010 - Career Point

12. A metallic conductor of non-uniform cross-sectional
area is shown in figure.
i
a
p 1 p 2 p 3
(i) Out of p 1 , p 2 , and p 3 at which point the drift speed
of the electron is maximum.
(ii) Out of p 1 , p 2 and p 3 at which point the current
density is minimum.
13. Stopping potential versus freq. of the incident light
graph is shown in figure for metal-1 and metal-2
metal-1 metal-2
V 0
θ 1
(i) Which metal will have the higher value of
threshold wavelength.
(ii) Is θ 1 = θ 2 if yes then why ?
14. Draw the circuit diagram for finding the internal
resistance of the cell using potentiometer.
15. (i) Define angle of Dip.
(ii) What is the value of angle of Dip at a place on
earth where Horizontal component and vertical
component of earth magnetic field are equal.
16. (i) State Kirchhoff's current law.
(ii) Find the potential difference across the 2 ohm
resistance for the given circuit diagram.
4A 1Ω 2Ω
θ 2
b
υ
18. (i) Write the order of colors in secondary rainbow.
(ii) Why sun appears reddish at the time of sunrise
and sunset.
19. The charges on the capacitors are Q a , Q b and Q c then
calculate -
1µF
Q a
12µF
30V
Q b
Q c
key-K
3µF
(i) Ratio of energy stored in 1 µF and 3 µF capacitor.
(ii) Potential difference across 12 µF capacitor
(iii) Energy supplied by the battery.
20. (i) A uniform magnetic field of 0.5 T exist in the
given solenoid. If an electron is projected along the
axis of solenoid from a towards b with the speed of
3 × 10 2 m/s then find the Lorentz force working on
electron.
i
a
(ii) When the current flows through the metallic
spring why it get shrinked.
21. (i) For the given circuit diagram find the position of
the null point.
5Ω 10 Ω
b
3Ω
A
B
1A
G
100 cm
17. (i) State Lenz's law.
(ii) If the current i increases then what will be the
direction of induced current in the circular coil for the
given figure.
V bb
R h
Key-k
Rheostat
(ii) For the given figure draw truth table.
A
i
b
B
Y
a
a >> b
XtraEdge for IIT-JEE 70 DECEMBER 2009