1
AIPMT 2010 Prelims
+4
-1
A beam of cathode rays is subjected to crossed electric (E) and magnetic fields (B). The fields are adjusted such that the beam is not deflected. The specific charge of the cathode rays is given by

(Where V is the potential difference between cathode and anode)
A
$${{{B^2}} \over {2V{E^2}}}$$
B
$${{2V{B^2}} \over {{E^2}}}$$
C
$${{2V{E^2}} \over {{B^2}}}$$
D
$${{{E^2}} \over {2V{B^2}}}$$
2
AIPMT 2010 Prelims
+4
-1
The potential difference that must be applied to stop the fastest photoelectrons emitted by a nickel surface, having work functions 5.01 eV, when ultraviolet light of 200 nm falls on it, must be
A
2.4 V
B
$$-$$ 1.2 V
C
$$-$$ 2.4 V
D
1.2 V
3
AIPMT 2010 Prelims
+4
-1
A source S1 is producing, 1015 photons per second of wavelength 5000 $$\mathop A\limits^ \circ$$. Another source S2 is producing 1.02 $$\times$$ 1015 photons per second of wavelength 5100 $$\mathop A\limits^ \circ$$. Then, (power of S2)/(power of S1) is equal to
A
1.00
B
1.02
C
1.04
D
0.98
4
AIPMT 2009
+4
-1
The number of photo electrons emitted for light of a frequency $$\upsilon$$ (higher than the threshold frequency $${\upsilon _0}$$) is proportional to
A
threshold frequency $$\left( {{\upsilon _0}} \right)$$
B
intensity of light
C
frequency of light $$\left( {{\upsilon _0}} \right)$$
D
$$\upsilon - {\upsilon _0}$$
EXAM MAP
Medical
NEET