As per this diagram a point charge +q is placed at the origin O. Work done in taking another point charge -Q from the point A [coordinates (O, a)] to another point B [coordinates (a, O)] along the straight path AB is
zero
For the network shown in the figure, the value of the current i is
B.
The circuit given resembles the balanced Wheatstone Bridge as
Thus, a middle arm containing 4 Ω resistance will be ineffective and no current flows through it. The equivalent circuit is shown as below:
Net resistance of AB and BC
R' = 4 + 2 = 6 Ω
Net resistance of AD and DC
R'' = 6 + 3 = 9 Ω
Thus parallel combination of R' and R'' gives
If the magnetic dipole moment of an atom of diamagnetic material, paramagnetic material and ferromagnetic material are denoted by respectively, then
In a circuit, L, C and R are connected in series with an alternating voltage source of frequency f. The current leads the voltage by 45°. The value of C is
When a wire of uniform cross-section a, length land resistance R is bent into a complete circle, resistance between two of dimetrically opposite points will be
4R
An electron moves in a circular orbit with a uniform speed v. It produces a magnetic field B at the centre of the circle. The radius of the circle is proportional, to
B/v
v/B
√v/B
√B/v
In the reaction, if the binding energies of are respectively a, b and c (in MeV), then the energy in this reaction is released in this reaction is
c + a - b
c - a - b
a + b + c
a +b - c
The work functions for metals A, B and C are respectively 1.92 eV, 2.0 eV and 5 eV. According to Einstein's equation, the metals which will emit photoelectrons for a radiation length 4100 Ao is /are
none
A only
A and B only
all the three metals