A metallic sheet is inserted between the plates of a parallel plate capacitor. The capacitance of the capacitor
|
(a) Increases |
|
(b) Is independent of the position of the sheet |
|
(c) Is maximum when the metal sheet in the middle |
|
(d) a, b |
(d) a, b
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
To charges 
and 
are placed 30 cm apart, shown in the figure. A third charge 
is moved along the arc of a circle of radius 40 cm from C to D. The change in the potential energy of the system is 
, where k is
|
(a) 8
|
(b) 
|
(c) 
|
(d) 
|
The rays of different colours fail to converge at a point after going through a converging lens. This defect is called:
When a hydrogen atom is raised from the ground state to an excited state
|
(a) P.E. increases and K.E. decreases |
|
(b) P.E. decreases and K.E. increases |
|
(c) Both kinetic energy and potential energy increase |
|
(d) Both K.E. and P.E. decrease |
Kinetic energy with which the electrons are emitted from the metal surface due to photoelectric effect is
|
(a) Independent of the intensity of illumination |
|
(b) Independent of the frequency of light |
|
(c) Inversely proportional to the intensity of illumination |
|
(d) Directly proportional to the intensity of illumination |
Three equal resistors connected in series across a source of e.m.f. together dissipate 10 watt. If the same resistors are connected in parallel across the same e.m.f., then the power dissipated will be
|
(a) 10 watt |
(b) 30 watt |
(c) 10/3 watt |
(d) 90 watt |
A radioactive sample of U238 decay to Pb through a process for which half life is 4.5 × 109 years. The ratio of number of nuclei of Pb to U238 after a time of 1.5 × 109 years (given 21/3 = 1.26)
|
(a) 0.12 |
(b) 0.26 |
(c) 1.2 |
(d) 0.37 |