Explanation:
As the capacitor is charged by using cell so potential as well as filed between the plates become constant.
For removing dielectric the capacitance becomes C/ k. Thus capacitance decreases by a factor of k.
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The diffraction effect can be observed in
|
(a) Only sound waves |
(b) Only light waves |
|
(c) Only ultrasonic waves |
(d) Sound as well as light waves |
A small cylindrical soft iron piece is kept in a galvanometer so that
|
(a) A radial uniform magnetic field is produced |
|
(b) A uniform magnetic field is produced |
|
(c) There is a steady deflection of the coil |
|
(d) All of these |
The distance between the two charges +q and -q of a dipole is r. On the axial line at a distance d from the centre of dipole, the intensity is proportional to
|
(a) |
(b) |
(c) |
(d) |
A radio transmitter operates at a frequency of 880 kHz and a power of 10 kW. The number of photons emitted per second are
|
(a) 1.72 |
(b) 1327 |
(c) 13.27 |
(d) 0.075 |
The resistance of a galvanometer is 50 ohms and the current required to give full scale deflection is 100μA. In order to convert it into an ammeter, reading upto 10A, it is necessary to put a resistance of
|
(a) 5 |
(b) 5 |
|
(c) |
(d) 99,950 |
A coil of resistance 10 W and an inductance 5H is connected to a 100 volt battery. Then energy stored in the coil is
|
(a) 125 erg |
(b) 125 J |
(c) 250 erg |
(d) 250 J |
For a cell of e.m.f. 2V, a balance is obtained for 50 cm of the potentiometer wire. If the cell is shunted by a 2Ω resistor and the balance is obtained across 40 cm of the wire, then the internal resistance of the cell is
|
(a) 0.25 Ω |
(b) 0.50 Ω |
(c) 0.80 Ω |
(d) 1.00 Ω |
