- ASilver
- BCopper
- CNichrome
- DGermanium
Explanation:
Alloys have high resistivity. The resistivity of nichrome has weak temperature dependence. At absolute zero, a pure metal has negligibly small resistivity while an alloy like nichrome has some residual resistivity.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
While using an electric bulb, the reflection for street lighting should be from
|
(a) Concave mirror |
(b) Convex mirror |
(d) Parabolic mirror |
(d) Parabolic mirror |
In a photo cell, the photo-electrons emission takes place
|
(a) After 10–1 sec on incident of light rays |
|
(b) After 10–3 sec on incident of light rays |
|
(c) After 10–6 sec on incident of light rays |
|
(d) After 10–8 sec on incident of light rays |
Assertion : The mass of b-particles when they are emitted is higher than the mass of electrons obtained by other means.
Reason : b-particle and electron, both are similar particles.
|
(a) If both assertion and reason are true and the reason is the correct explanation of the assertion. |
|
(b) If both assertion and reason are true but reason is not the correct explanation of the assertion. |
|
(c) If assertion is true but reason is false. |
|
(d) If the assertion and reason both are false. |
The radius of a metallic sphere if its capacitance is 1/9 F, is
|
(a) |
(b) |
(c) |
(d) |
For intensity I of a light of wavelength 5000Å the photoelectron saturation current is 0.40 μA and stopping potential is 1.36 V, the work function of metal is
|
(a) 2.47 eV |
(b) 1.36 eV |
(c) 1.10 eV |
(d) 0.43 eV |
Two resistances are connected in two gaps of a metre bridge. The balance point is 20 cm from the zero end. A resistance of 15 ohms is connected in series with the smaller of the two. The null point shifts to 40 cm. The value of the smaller resistance in ohms is
|
(a) 3 |
(b) 6 |
(c) 9 |
(d) 12 |
Moment of inertia of a magnetic needle is 40 gm-cm2 has time period 3 seconds in earth's horizontal field = 3.6
weber/m2. Its magnetic moment will be
|
(a) 0.5 |
(b) 5 |
(c) 0.250 |
(d) 5 |