- AEmitted
- BAbsorbed
- CBoth absorbed and emitted
- DDepends on the energy levels of the orbits
Explanation:
When an electron jumps from lower energy level to higher energy level it absorbs energy and when it jumps from higher energy level to lower energy level it emits energy.
So whether the electron emits or absorbs energy depends on the energy levels of the orbit
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
A straight wire of length ( metre is carrying a current of 2A and the magnetic field due to it is measured at a point distant 1 cm from it. If the wire is to be bent into a circle and is to carry the same current as before, the ratio of the magnetic field at its centre to that obtained in the first case would be
|
(a) 50 : 1 |
(b) 1 : 50 |
(c) 100 : 1 |
(d) 1 : 100 |
Assertion : In transistor common emitter mode as an amplifier is preferred over common base mode.
Reason : In common emitter mode the input signal is connected in series with the voltage applied to the base emitter function.
|
(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. |
Match the List I with the List II from the combination shown. In the left side (List I) there are four different conditions and in the right side (List II), there are ratios of heat produced in each resistance for each condition :
|
List I |
List II |
||
|
(I) |
Two wires of same resistance are connected in series and same current is passed through them |
(A) |
1 : 2 |
|
(II) |
Two wires of resistance R and 2R ohm are connected in series and same P.D. is applied across them |
(B) |
4 : 1 |
|
(III) |
Two wires of same resistance are connected in parallel and same current is flowing through them |
(C) |
1 : 1 |
|
(IV) |
Two wires of resistances in the ratio 1 : 2 are connected in parallel and same P.D. is applied across them |
(D) |
2 : 1 |
|
(a) I – B; II – A; III – C; IV - D |
(b) I – C; II – D; III – C; IV - D |
|
(c) I – B; II – D; III – A; IV - C |
(d) I – A; II – B; III – D; IV - C |
4 eV is the energy of the incident photon and the work function in 2eV. What is the stopping potential
|
(a) 2V |
(b) 4V |
(c) 6V |
(d) 2 |

When N-type of semiconductor is heated
|
(a) Number of electrons increases while that of holes decreases |
|
(b) Number of holes increases while that of electrons decreases |
|
(c) Number of electrons and holes remains same |
|
(d) Number of electrons and holes increases equally |
The resistivity of a wire depends on its
|
(a) Length |
(b) Area of cross-section |
(c) Shape |
(d) Material |