Question

Assertio : Hydrogen atom consists of only one electron but its emission spectrum has many lines.  

Reason  : Only Lyman series is found in the absorption spectrum of hydrogen atom whereas in the emission spectrum, all the series are found.

(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.

(c) If assertion is true but reason is false.

(d) If the assertion and reason both are false.

Answer

(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

When a thin metal plate is placed in the path of one of the interfering beams of light

(a) Fringe width increases  

 (b) Fringes disappear

(c) Fringes become brighter

(d) Fringes becomes blurred

A flat circular disc has a charge +Q uniformly distributed on the disc. A charge +q is thrown with kinetic energy  E towards the disc along its normal axis. The charge q  will

(a) Hit the disc at the centre

(b) Return back along its path after touching the disc

(c) Return back along its path without touching the disc

(d) Any of the above three situations is possible depending on the magnitude of E

A ray of light is incident on the surface of separation of a medium at an angle 45° and is refracted in the medium at an angle 30°. What will be the velocity of light in the medium

(a) 1.98

(b)  2.12  

(c) 3.18  

(d) 3.33  

When there is an electric current through a conducting wire along its length, then an electric field must exist

(a)  Outside the wire but normal to it

(b) Outside the wire but parallel to it

(c) Inside the wire but parallel to it

(d) Inside the wire but normal to it

One conducting U tube can slide inside another as shown in figure, maintaining electric contacts between the tubes. The magnetic field B is perpendicular to the plane of the figure. If each tube moves towards the other at a constant speed v, then the emf induced in the circuit in terms of B, l and v where l is the width of each tube, will be

A sphere of radius R has a uniform distribution of electric charge in its volume. At a distance x from its centre, for x < R, the electric field is directly proportional to

(a)  

(b)  

(c) x  

(d)  

Two coherent sources of intensity ratio 1 : 4 produce an interference pattern. The fringe visibility will be

(a) 1

(b) 0.8

(c) 0.4

(d)  0.6

If a magnet is hanged with its magnetic axis then it stops in

(a) Magnetic meridian

(b) Geometric meridian

(c) Angle of dip

(d) None of these

AB is a potentiometer wire of length 100 cm and its resistance is 10 ohms.  It is connected in series with a resistance R = 40 ohms and a battery of e.m.f. 2 V and negligible internal resistance.  If a source of unknown e.m.f. E is balanced by 40 cm length of the potentiometer wire, the value of E is

(a) 0.8 V 

(b) 1.6 V

(c) 0.08 V 

(d) 0.16 V

A potentiometer wire of length 1 m and resistance 10 W is connected in series with a cell of emf 2V with internal resistance 1 W and a resistance box including a resistance R.  If potential difference between the ends of the wire is 1 mV, the value of R is

(a) 20000 W

(b) 19989 W

(c) 10000 W

(d) 9989 W