An oil drop having charge 2e is kept stationary between two parallel horizontal plates 2.0 cm apart when a potential difference of 12000 volts is applied between them. If the density of oil is 900 kg/m3, the radius of the drop will be
|
(a) 2.0 |
(b) 1.7 |
(c) 1.4 |
(d) 1.1 |
(b) 1.7 
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A potential difference of 42,000 volts is used in an X-ray tube to accelerate electrons. The maximum frequency of the X–radiations produced is (1 eV = 1.6 
and h = 6.63 
(a) 
|
(b)
|
(c)
|
(d) 
|
The mass equivalent of 931 MeV energy is
|
(a) 1.66 |
(b) 6.02 |
(c) 1.66 |
(d) 6.02 |
Beams of light are incident through the holes A and B and emerge out of the box through the holes C and D respectively as shown in the Figure. Which of the following could be inside the box?
The charges on two sphere are +7mC and – 5mC respectively. They experience a force F. If each of them is given and additional charge of – 2mC, the new force of attraction will be
|
(a) F |
(b) F / 2 |
(c) F/ |
(d) 2F |
The resultant magnetic moment of neon atom will be
|
(a) Infinity |
(b) mB |
(c) Zero |
(d) mB/2 |
