When Ge crystals are doped with phosphorus atom, then it becomes
|
(a) Insulator |
(b) P-type |
(c) N-type |
(d) Superconductor |
When Ge crystals are doped with phosphorus atom, then it becomes
|
(a) Insulator |
(b) P-type |
(c) N-type |
(d) Superconductor |
(c) N-type
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Average energy stored in a pure inductance L when a current i flows through it, is
|
(a) |
(b) |
(c) |
(d) |
If in Rutherford’s experiment, the number of particles scattered at 90° angle are 28 per min, then number of scattered particles at an angle 60° and 120° will be
|
(a) 112/min, 12.5/min |
(b) 100/min, 200/min |
(c) 50/min, 12.5/min |
(d) 117/min, 25/min |
The Bohr model of atoms
|
(a) Assumes that the angular momentum of electrons is quantized |
|
(b) Uses Einstein’s photo-electric equation |
|
(c) Predicts continuous emission spectra for atoms |
| (d) Predicts the same emission spectra for all types of atoms |
The condition for a uniform spherical mass m of radius r to be a black hole is [G = gravitational constant and g = acceleration due to gravity]
|
(a) |
(b) |
(c) |
(d) |
A small square loop of wire of side l is placed inside a large square loop of wire of side L (L > l). The loop are coplanar and their centre coincide. The mutual inductance of the system is proportional to
|
(a) l / L |
(b) |
(c) L/l |
(d) |
A charged particle q is shot towards another charged particle Q which is fixed, with a speed v. It approaches Q upto a closest distance r and then returns. If q were given a speed 2v, the closest distances of approach would be
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|
(a) r |
(b) 2r |
(c) r/2 |
(d) r/4 |
The mechanism of the hydrogen bomb is based on
|
(a) Fission of isotopes of hydrogen |
(b) Fusion of protons |
|
(c) Fusion of deutrium and tritium |
(d) Fusion of neutrons |
A rod of length 20 cm is rotating with angular speed of 100 rps in a magnetic field of strength 0.5 T about it’s one end. What is the potential difference between two ends of the rod
|
(a) 2.28 V |
(b) 4.28 V |
(c) 6.28 V |
(d) 2.5 V |