A coil having an area 
is placed in a magnetic field which changes from 
to 
in a time interval t. The e.m.f. induced in the coil will be
|
(a) |
(b) |
(c) 
|
(d) 
|
(a) 
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
In X-ray experiment Ka, Kb denotes
|
(a) Characteristic |
(b) Continuous wavelength |
|
(c) a, b-emissions respectively |
(d) None of these |
Symbolic representation of photodiode is
|
(a)
|
(b)
|
(c)
|
(d)
|
The first excited state of hydrogen atom is 10.2 eV above its ground state. The temperature is needed to excite hydrogen atoms to first excited level, is
(a) 7.9 
|
(b) 3.5
|
(c) 5.8
|
(d) 14
|
The magnetic field lines due to a bar magnet are correctly shown in
|
(a)
|
(b)
|
(c)
|
(d)
|
The relationship between λ and half life (
of a radioactive substance is
|
(a) λ = |
(b) λ = |
(c) λ = |
(d) λ = |
The resistance of a discharge tube is
|
(a) Ohmic |
(b) Non-ohmic |
(c) Both (a) and (b) |
(d) Zero |
A sinusoidal voltage of peak value 200 volt is connected to a diode and resistor R in the circuit shown so that half wave rectification occurs. If the forward resistance of the diode is negligible compared to R the rms voltage (in volt) across R is approximately
|
(a) 200 |
(b) 100 |
(c) |
(d) 280 |
There are three voltmeters of the same range but of resistances 1000Ω, 8000 Ω and 4000 Ω respectively. The best voltmeter among these is the one whose resistance is
|
(a) 10000 W |
(b) 8000 W |
(c) 4000 W |
(d) All are equally good |
