MCQ
The photoelectric effect proves that light consists of :
- APhotons
- BElectrons
- CElectromagnetic waves
- DMechanical waves
✓
Answer
- Photons
Explanation:
It's been determined experimentally that when light shines on a metal surface, the surface emits electrons. For example, you can start a current in a circuit just by shining a light on a metal plate. we were saying earlier that light is made up of electromagnetic waves, and that the waves carry energy. So if a wave of light hit an electron in one of the atoms in the metal, it might transfer enough energy to knock the electron out of its atom. Light has sometimes been viewed as a particle (photon) rather than a wave. If it's waves, the energy contained in one of those waves should depend only on its amplitude--that is, on the intensity of the light.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Banding of a stick when placed in water is because:
Vertical component of earth's magnetic field is zero:
A point charge q is placed at a distance a/2 directly above the centre of a square of side a. The electric flux through the square is
|
(a) |
(b) |
(c) |
(d) |
Which logic gate produces LOW output when any of the inputs is HIGH?
A steady current i is flowing through a conductor of uniform cross-section. Any segment of the conductor has
|
(a) Zero charge |
(b) Only positive charge |
|
(c) Only negative charge |
(d) Charge proportional to current i |
When an electric dipole 
is placed in a uniform electric field 
then at what angle between and the value of torque will be maximum
|
(a) 90° |
(b) 0° |
(c) 180° |
(d) 45° |
100 cells each of e.m.f. 5 V and internal resistance 1 ohm are to be arranged so as to produce maximum current in a 25 ohms resistance. Each row is to contain equal number of cells. The number of rows should be
|
(a) 2 |
(b) 4 |
(c) 5 |
(d) 10 |
The load voltage is approximately constant when a zener diode is:
The reactance of a circuit is zero. It is possible that the circuit contains.
Tesla is a unit of: