1
JEE Main 2021 (Online) 17th March Evening Shift
Numerical
+4
-1
Change Language
Seawater at a frequency f = 9 $$\times$$ 102 Hz, has permittivity $$\varepsilon $$ = 80$$\varepsilon $$0 and resistivity $$\rho$$ = 0.25 $$\Omega$$m. Imagine a parallel plate capacitor is immersed in seawater and is driven by an alternating voltage source V(t) = V0 sin(2$$\pi$$ft). Then the conduction current density becomes 10x times the displacement current density after time t = $${1 \over {800}}$$s. The value of x is _____________. (Given : $${1 \over {4\pi {\varepsilon _0}}} = 9 \times {10^9}$$ Nm2C$$-$$2)
Your input ____
2
JEE Main 2021 (Online) 17th March Morning Shift
Numerical
+4
-1
Change Language
If 2.5 $$\times$$ 10$$-$$6 N average force is exerted by a light wave on a non-reflecting surface of 30 cm2 area during 40 minutes of time span, the energy flux of light just before it falls on the surface is ___________ W/cm2. (Round off to the Nearest Integer)

(Assume complete absorption and normal incidence conditions are there)
Your input ____
3
JEE Main 2021 (Online) 26th February Morning Shift
Numerical
+4
-1
Change Language
A radiation is emitted by 1000W bulb and it generates an electric field and magnetic field at P, placed at a distance of 2m. The efficiency of the bulb is 1.25%. The value of peak electric field at P is x $$\times$$ 10$$-$$1 V/m. Value of x is ___________. (Rounded off to the nearest integer) [Take $${\varepsilon _0} = 8.85 \times {10^{ - 12}}$$ C2N$$-$$1 m$$-$$2, c = $$3 \times {10^8}$$ ms$$-$$1]
Your input ____
4
JEE Main 2021 (Online) 25th February Evening Shift
Numerical
+4
-1
Change Language
The peak electric field produced by the radiation coming from the 8W bulb at a distance of 10 m is $${x \over {10}}\sqrt {{{{\mu _0}c} \over \pi }} {V \over m}$$. The efficiency of the bulb is 10% and it is a point source. The value of x is ___________.
Your input ____
JEE Main Subjects
EXAM MAP
Medical
NEET
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN
Civil Services
UPSC Civil Service
Defence
NDA
CBSE
Class 12