An ionization chamber with parallel conducting plates as anode and cathode has 5 
electrons and the same number of singly-charged positive ions per 
. The electrons are moving at 0.4 m/s. The current density from anode to cathode is 
. The velocity of positive ions moving towards cathode is
|
(a) 0.4 m/s |
(b) 16 m/s |
(c) Zero |
(d) 0.1 m/s |
(d) 0.1 m/s
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The wavelength of the first line of Balmer series is 6563 
. The Rydberg constant for hydrogen is about
|
(a) 1.09 |
(b) 1.09 |
(c) 1.09 |
(d) 1.09 |
Which of the following plots may represent the thermal energy produced in a resistor in a given time as a function of the electric current
|
(a) a |
(b) b |
(c) c |
(d) d |
If 
and 
are respectively the filament resistances of a 200 watt bulb and 100 watt bulb designed to operate on the same voltage, then
|
(a) |
(b) |
|
(c) |
(d) |
The universal property of all substances is
|
(a) Diamagnetism |
(b) Ferromagnetism |
(c) Paramagnetism |
(d) All of these |
It is desired to photograph the image of an object placed at a distance of 3m from the plane mirror. The camera which is at a distance of 4.5 m from the mirror should be focussed for a distance of
| (a) 3m | (b) 4.5m | (c) 6m | (d) 7.5 m |
$\lambda'>\lambda$
$\lambda'=\lambda$
$\lambda'<\lambda$
Consider the circuit given here with the following parameters E.M.F. of the cell = 12 V. Internal resistance of the cell = 2 Ω. Resistance R = 4 Ω
Which one of the following statements in true
|
(a) Rate of energy loss in the source is = 8 W |
|
(b) Rate of energy conversion in the source is 16 W |
|
(c) Power output in is = 8 W |
|
(d) Potential drop across R is = 16 V |
In NPN transistor, 1010 electrons enters in emitter region in 10–6 sec. If 2% electrons are lost in base region then collector current and current amplification factor (b) respectively are
|
(a) 1.57 mA, 49 |
(b) 1.92 mA, 70 |
(c) 2 mA, 25 |
(d) 2.25 mA, 100 |
