- ACell
- BBattery
- CGenerator
- DAll of these
Explanation:
A source of EMF can be cell, battery or generator.
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An X-ray machine has an accelerating potential difference of 25,000 volts. By calculation the shortest wavelength will be obtained as (h = 6.63
; e =
coulomb)
|
(a) 0.25 Å |
(b) 0.50 Å |
(c) 1.00 Å |
(d) 2.50 Å |
Half life of a radioactive element is 10 days. The time during which quantity remains 1/10 of initial mass will be
|
(a) 100 days |
(b) 50 days |
(c) 33 days |
(d) 16 days |
Hydrogen atom emits blue light when it changes from n = 4 energy level to the n = 2 level. Which colour of light would the atom emit when it changes from the n = 5 level to the n = 2 level
|
(a) Red |
(b) Yellow |
(c) Green |
(d) Violet |
A coil is wound as a transformer of rectangular cross-section. If all the linear dimensions of the transformer are increased by a factor 2 and the number of turns per unit length of the coil remain the same, the self inductance increased by a factor of
|
(a) 16 |
(b) 12 |
(c) 8 |
(d) 4 |
The maximum value of stopping potential in the following diagram is

|
(a) – 4V |
(b) – 1V |
(c) – 3V |
(d) – 2V |
The primary winding of transformer has 500 turns whereas its secondary has 5000 turns. The primary is connected to an ac supply of 20 V, 50 Hz. The secondary will have an output of
|
(a) 200 V, 50 Hz |
(b) 2 V, 50 Hz |
(c) 200 V, 500 Hz |
(d) 2 V, 5 Hz |
Intrinsic semiconductor is electrically neutral. Extrinsic semiconductor having large number of current carriers would be
|
(a) Positively charged |
|
(b) Negatively charged |
|
(c) Positively charged or negatively charged depending upon the type of impurity that has been added |
|
(d) Electrically neutral |
Two condensers of capacity 0.3 μF and 0.6 μF respectively are connected in series. The combination is connected across a potential of 6 volts . The ratio of energies stored by the condensers will be
|
(a) |
(b) 2 |
(c) |
(d) 4 |
A network of four capacitors of capacity equal to
and
are conducted in a battery as shown in the figure. The ratio of the charges on
and
is

|
(a) |
(b) |
(c) |
(d) |