- A$V \propto r$
- ✓$V =$ constant
- C$V \propto \frac{1}{r}$
- D$V \propto \frac{1}{r^2}$
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In the Bohr model of a hydrogen atom, the centripetal force is furnished by the coulomb attraction between the proton and the electron. If
is the radius of the ground state orbit, m is the mass, e is the charge on the electron and
is the vacuum permittivity, the speed of the electron is
|
(a) 0 |
(b) |
(c) |
(d) |
A charged particle of mass 0.003 gm is held stationary in space by placing it in a downward direction of electric field of 6
. Then the magnitude of the charge is
|
(a) 5 |
(b) 5 |
(c) -18 |
(d) -5 |
A car is moving with at a constant speed of 60kmh-1 on a straight road. Looking at the rear view mirror, the driver finds that the car following him is at a distance of 100m and is approaching with a speed of 5kmh-1. In order to keep track of the car in the rear, the driver begins to glance alternatively at the rear and side mirror of his car after every 2s till the other car overtakes. If the two cars were maintaining their speeds, which of the following statement (s) is/are correct?
An infinite ladder network is arranged with resistances R and 2 R as shown. The effective resistance between terminals A and B is
|
(a) ∞ |
(b) R |
(c) 2 R |
(d) 3 R |
On adjusting the P-N junction diode in forward biased
|
(a) Depletion layer increases |
(b) Resistance increases |
|
(c) Both decreases |
(d) None of these |
In a semiconductor the separation between conduction band and valence band is of the order of
|
(a) 100 eV |
(b) 10 eV |
(c) 1eV |
(d) 0 eV |