- AAbsorbs light and produces a stream of electrons
- BAbsorb a stream of electron and produces light
- CConverts protons into photons
- DConverts photons into protons
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
If the radioactive decay constant of radium is 1.07
per year, then its half life period is approximately equal to
|
(a) 8,900 years |
(b) 7,000 years |
(c) 6,476 years |
(d) 2,520 years |
The time taken by sunlight to cross a 5 mm thick glass plate (μ = 3/2) is
|
(a) 0.25 |
(b) 0.167 |
(c) 2.5 |
(d) 1.0 |
$\text{F = Mg}$
$\text{F}=\mu\text{Mg}$
$\text{Mg}\leq\text{F}\leq\text{Mg}\sqrt{1+\mu^2}$
$\text{Mg}\geq\text{F}\geq\text{Mg}\sqrt{1-\mu^2}.$
A cell of e.m.f 1.5 V having a finite internal resistance is connected to a load resistance of 2Ω. For maximum power transfer the internal resistance of the cell should be
|
(a) 4 ohm |
(b) 0.5 ohm |
(c) 2 ohm |
(d) None of these |
In the following Wheatstone bridge P/Q = R/S. If key K is closed, then the galvanometer will show deflection
|
(a) In left side |
(b) In right side |
(c) No deflection |
(d) In either side |
Assertion : Interference pattern is made by using blue light instead of red light, the fringes becomes narrower.
Reason : In Young’s double slit experiment, fringe width is given by relation B =
|
(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. |
An e.m.f. of 12 volt is produced in a coil when the current in it changes at the rate of 45 amp/minute. The inductance of the coil is
|
(a) 0.25 henry |
(b) 1.5 henry |
(c) 9.6 henry |
(d) 16.0 henry |
In charging a battery of motor-car, the following effect of electric current is used
|
(a) Magnetic |
(b) Heating |
(c) Chemical |
(d) Induction |