MCQ
The main defect of Bohr's atom model is :
- Amixing of classical and quantum theories
- Bexclusion of nuclear motion
- Cfailed to explain the fine structure of spectral lines
- Dfailed to explain larger atoms
✓
Answer
- failed to explain larger atoms
Explanation:
Bohr's model can only clearly explain hydrogen or hydrogen-like atoms, it fails when applied to larger and heavier atoms like iron, gold, mercury, etc.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
An ideal coil of 10 henry is joined in series with a resistance of 5 ohm and a battery of 5 volt. 2 second after joining, the current flowing in ampere in the circuit will be
|
(a) |
(b) |
(c) (1 – e) |
(d) e |
As the mass number A increases, the binding energy per nucleon in a nucleus:
- Increases.
- Decreases.
- Remains the same.
- Varies in a way that depends on the actual value of A.
Two identically charged spheres when suspended by strings of equal lengths make an angle of 30∘ with each other. The angle remains the same when they are immersed in a liquid of density less than the density of the material of the spheres. Choose the correct option
denotes the mass of a proton and 
that of a neutron. A given nucleus, of binding energy B, contains Z protons and N neutrons. The mass M(N, Z) of the nucleus is given by (c is the velocity of light)
(a) 
|
(b) 
|
(c) 
|
(d) 
|
The cold junction of a thermocouple is maintained at 10℃. No thermo e.m.f. is developed when the hot junction is maintained at 530 ℃ . The neutral temperature is
|
(a) 260℃ |
(b) 270℃ |
(c) 265℃ |
(d) 520℃ |
The figure shows a double slit experiment P and Q are the slits. The path lengths PX and QX are nλ and (n+2)λ respectively, where n is a whole number and λ is the wavelength. Taking the central fringe as zero, what is formed at X
|
(a) First brigh |
(b) First dark |
(c) Second bright |
(d) Second dark |
The characteristic impedance of a coaxial cable is of the order of
|
(a) 50 W |
(b) 200 W |
(c) 270 W |
(d) None of these |
In a projectile motion the velocity:
- Is always perpendicular to the acceleration.
- Is never perpendicular to the acceleration.
- Is perpendicular to the acceleration for one instant only.
- Is perpendicular to the acceleration for two instants.
The momentum in mechanics is expressed as m × v. The analogous expression in electricity is
|
(a) I × Q |
(b) I × V |
(c) L × I |
(d) L × Q |
When the charged particles move in a combined magnetic and electric field, then the force acting is known as _________.