Wavefront means
|
(a) All particles in it have same phase |
|
(b) All particles have opposite phase of vibrations(c) Few particles are in same phase, rest are in opposite phase |
|
(c) Few particles are in same phase, rest are in opposite phase |
|
(d) None of these |
(a) All particles in it have same phase
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
$\text{v}$
$\frac{\text{v}}{2}$
$2\text{v}$
$\sqrt{2}\text{v}.$
Which of the following statements is true for an N-type semi-conductor
|
(a) The donor level lies closely below the bottom of the conduction band |
|
(b) The donor level lies closely above the top of the valence band |
|
(c) The donor level lies at the halfway mark of the forbidden energy gap |
|
(d) None of above |
Self induction of a solenoid is
|
(a) Directly proportional to current flowing through the coil |
|
(b) Directly proportional to its length |
|
(c) Directly proportional to area of cross-section |
|
(d) Inversely proportional to area of cross-section |
Light takes 8 min 20 sec to reach from sun on the earth. If the whole atmosphere is filled with water, the light will take the time (a
|
(a) 8 min 20 sec |
(b) 8 min |
(c) 6 min 11 sec |
(d) 11 min 6 sec |
In charging a battery of motor-car, the following effect of electric current is used
|
(a) Magnetic |
(b) Heating |
(c) Chemical |
(d) Induction |
12 cells each having same emf are connected in series with some cells wrongly connected. The arrangement is connected in series with an ammeter and two cells which are in series. Current is 3 A when cells and battery aid each other and is 2 A when cells and battery oppose each other. The number of cells wrongly connected is
|
(a) 4 |
(b) 1 |
(c) 3 |
(d) 2 |
If eight identical drops are joined to form a bigger drop, the potential on bigger as compared to that on smaller drop will be
|
(a) Double |
(b) Four times |
(c) Eight times |
(d) One time |