11). On a rainy day, small oil films on water show brilliant colours. This is due to
| A). dispersion |
| B). interference |
| C). diffraction |
| D). polarization |
|
12). Lux is the SI unit of
| A). intensity of illumination |
| B). luminous efficiency |
| C). luminous flux |
| D). luminous intensity |
|
13). Rectifiers are used to convert
| A). Direct current to Alternating current |
| B). Alternating current to Direct current |
| C). high voltage to low voltage |
| D). low voltage to high voltage |
|
14). Pick out the scalar quantity
| A). force |
| B). pressure |
| C). velocity |
| D). acceleration |
|
15). If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same
| A). velocity |
| B). momentum |
| C). acceleration |
| D). kinetic energy |
|
16). Out of the following pairs, choose the pair in which the physical quantities do not have identical dimension?
| A). Pressure and Young's modules |
| B). Planck's constant and Angular momentum |
| C). Impulse and moment of force |
| D). Force and rate of change of linear momentum |
|
17). Let a thin capillary tube be replaced with another tube of insufficient length then, we find water
| A). will overflow |
| B). will not rise |
| C). depressed |
| D). change its meniscus |
|
18). Metals are good conductors of electricity because
| A). they contain free electrons |
| B). the atoms are lightly packed |
| C). they have high melting point |
| D). All of the above |
|
19). Of the following properties of a wave, the one that is independent of the other is its
| A). amplitude |
| B). velocity |
| C). wavelength |
| D). frequency |
|
20). Find the maximum velocity for the overturn of a car moving on a circular track of radius 100 m. The co-efficient of friction between the road and tyre is 0.2
| A). 0.14 m/s |
| B). 140 m/s |
| C). 1.4 km/s |
| D). 14 m/s |
|
