- A1.66 × 10–19c/ kg.
- B9.1 × 1011c/ kg.
- C1.76 × 1011c/ kg.
- D9.1 × 1019c/ kg.
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Each atom of an iron bar (5cm × 1 cm × 1 cm) has a magnetic moment 1.8
. Knowing that the density of iron is 7.78
atomic weight is 56 and Avogadro's number is 6.02
the magnetic moment of bar in the state of magnetic saturation will be
|
(a) 4.75 |
(b) 5.74 |
(c) 7.54 |
(d) 75.4 |
The binding energy per nucleon of
is 7.97 MeV and that of
is 7.75 MeV. The energy (in MeV) required to remove a neutron from
is
|
(a) 3.52 |
(b) 3.64 |
(c) 4.23 |
(d) 7.86 |
If current flowing through shell of previous objective is equal to i, then energy density at a point distance 2R from axis of the shell varies according to the graph
|
(a)
|
(b)
|
(c)
|
(d)
|
In Thomson experiment of finding e/m for electrons, beam of electron is replaced by that of muons (particle with same charge as of electrons but mass 208 times that of electrons). No deflection condition in this case satisfied if
|
(a) B is increased 208 times |
(b) E is increased 208 times |
|
(c) B is increased 14.4 times |
(d) None of these |
A wire of length L and 3 identical cells of negligible internal resistances are connected in series. Due to current, the temperature of the wire is raised by ∆ T in a time t. A number N of similar cells is now connected in series with a wire of the same material and cross – section but of length 2 L. The temperature of the wire is raised by the same amount ∆ T in the same time t. the value of N is
|
(a) 4 |
(b) 6 |
(c) 8 |
(d) 9 |
If the potential difference applied across X-ray tube is V volts, then approximately minimum wavelength of the emitted X-rays will be
|
(a) |
(b) |
(c) |
(d) |
We can reduce eddy currents in the core of transformer
|
(a) By increasing the number of turns in secondary coil |
|
(b) By taking laminated core |
|
(c) By making step-down transformer |
|
(d) By using a weak ac at high potential |
A substance is behaving as convex lens in air and concave in water, then its refractive index is
|
(a) Smaller than air |
(b) Greater than both air and water |
|
(c) Greater than air but less than water |
(d) Almost equal to water |
What is the area of the plates of a 3F parallel plate capacitor, if the separation between the plates is 5mm
|
(a) 1.694 |
(b) 4.529 |
(c) 9.281 |
(d) 12.981 |