- AAs a rectifier.
- BFor converting light energy to electric energy.
- CFor getting light radiation.
- DFor increasing the amplitude of an AC signal
Explanation:
To increase the amplitude of an AC signal, transistors are used. p-n junction diodes can be used as rectifiers and in photo-diode and LED.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
An object is placed first at infinity and then at 20 cm from the object side focal plane of the convex lens. The two images thus formed are 5 cm apart. The focal length of the lens is
|
(a) 5 cm |
(b) 10 cm |
(c) 15 cm |
(d) 20 cm |
Assertion : A paramagnetic sample display greater magnetisation (for the same magnetising field) when cooled.
Reason : The magnetisation does not depend on temperature.
|
(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. |
The fact that electric charges are integral multiples of the fundamental electronic charge was proved experimentally by
|
(a) Planck |
(b) J.J. Thomson |
(c) Einstein |
(d) Millikan |
The figure shows a double slit experiment P and Q are the slits. The path lengths PX and QX are nλ and (n+2)λ respectively, where n is a whole number and λ is the wavelength. Taking the central fringe as zero, what is formed at X
|
(a) First brigh |
(b) First dark |
(c) Second bright |
(d) Second dark |
A solenoid has an inductance of 60 henrys and a resistance of 30 ohms. If it is connected to a 100 volt battery, how long will it take for the current to reach
of its final value
|
(a) 1 second |
(b) 2 seconds |
(c) e seconds |
(d) 2e seconds |
An electron and a proton are in a uniform electric field, the ratio of their accelerations will be
|
(a) Zero |
|
(b) Unity |
|
(c) The ratio of the masses of proton and electron |
|
(d) The ratio of the masses of electron and proton |