Recent Articles Related To Physics
Light travels a distance x in time t1 in air and 10x in time t2 in another denser medium. What is the critical angle for this medium? NEET UG 2023
In a plane electromagnetic wave travelling in free space, the electric field component oscillates sinusoidally at a frequency of 2.0 × 10^10 Hz and amplitude 48 V m^–1. Then the amplitude of oscillating magnetic field is (Speed of light in free space = 3 × 10^8 m s^–1)
V= E/B
for free space v=c
Putting all values in MKS (c=3 × 10^8, E=48 ) we get B=1.6 × 10^–7 Tesla
A full wave rectifier circuit consists of two p-n junction diodes, a centre-tapped transformer, capacitor and a load resistance. Which of these components remove the ac ripple from the rectified output?
Capacitor is used to remove AC ripples because voltage across it doesn't change rapidly so ripples of change are minimized.
AC have ripples because supply have variable voltage throughout its cycle.
One pn diode works in +ve cycle and another in negative cycle.
Center tapped transformer ensures supply of equal voltage to both diodes.
Load resistance is for output.
A 12 V, 60 W lamp is connected to the secondary of a step-down transformer, whose primary is connected to ac mains of 220 V. Assuming the transformer to be ideal, what is the current in the primary winding?
Ideal so power at primary(Pp) is eqaul to power at secondary(Ps)
Ps is 60Watt
Pp= VI where V is 220 Volt so I= 60/220 i.e. 0.27Ampere
The net magnetic flux through any closed surface is ? NEET UG2023
For closed surace (like cube, square, cuboid, cone, spherical shell etc) net magnetic flux is zero.
The work functions of Cesium (Cs), Potassium (K) and Sodium (Na) are 2.14 eV, 2.30 eV and 2.75 eV respectively. If incident electromagnetic radiation has an incident energy of 2.20 eV, which of these photosensitive surfaces may emit photoelectrons? NEET UG 2023
Basic Fact- For photoelctric emission to occur incident radiation must have energy(E) equal to or greater than work function(W) of the material, for given question E exceeds W for Cs only.
If the mass of the bob in simple pendulum is increased to thrice its original mass and its length is made half its original length, then the new time period of oscillation is x/2 times its original time period, what is value of x ? NEET UG 2024
A 10 μF capacitor is connected to a 210 V, 50 Hz source. The peak current in the capacitor will be ? CBSE, NEET, NTA-JEE, CUET
An iron bar of length L has magnetic moment M. It is bent at the middle of its length such that the two arms make an angle 60° with each other. The magnetic moment of this new magnet is? NEET UG2024
A small telescope has an objective of focal length 140 cm and an eye piece of focal length 5.0 cm. The magnifying power of telescope for viewing a distant object is ? NEET UG2024
