In the following reaction
is
|
(a) 28 |
(b) 27 |
(c) 26 |
(d) 22 |
In the following reaction
is
|
(a) 28 |
(b) 27 |
(c) 26 |
(d) 22 |
(b) 27
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In a transformer 220 ac voltage is increased to 2200 volts. If the number of turns in the secondary are 2000, then the number of turns in the primary will be
|
(a) 200 |
(b) 100 |
(c) 50 |
(d) 20 |
The basic magnetization curve for a ferromagnetic material is shown in figure. Then, the value of relative permeability is highest for the point

|
(a) P |
(b) Q |
(c) R |
(d) S |
A convex lens has a focal length f. It is cut into two parts along the dotted line as shown in the figure. The focal length of each part will be
|
(a) |
(b) f |
(c) |
(d) 2f |
In the nth orbit, the energy of an electron
for hydrogen atom. The energy required to take the electron from first orbit to second orbit will be
|
(a) 10.2 eV |
(b) 12.1 eV |
(c) 13.6 eV |
(d) 3.4 eV |
The electric resistance of a certain wire of iron is R. If its length and radius are both doubled, then
|
(a) The resistance will be doubled and the specific resistance will be halved |
|
(b) The resistance will be halved and the specific resistance will remain unchanged |
|
(c) The resistance will be halved and the specific resistance will be doubled |
|
(d) The resistance and the specific resistance, will both remain unchanged |
In an experiment, the saturation in the plate current in a diode is observed at 240V. But a student still wants to increase the plate current. It can be done, if
|
(a) The plate voltage is increased further |
|
(b) The plate voltage is decreased |
|
(c) The filament current is decreased |
|
(d) The filament current is increased |
The magnetic field lines due to a bar magnet are correctly shown in
|
(a)
|
(b)
|
(c)
|
(d)
|