Charges and Fields+Potentials and Capacitance
What is the net charge of an electric dipole?
Zero
Mention one condition for current flow.
Potential difference/conducting path
What is pitch in a magnetic field?
The distance moved along the magnetic field in one rotation.
What type of EM Waves are used in LASIK Surgery?
UV Rays
What is the working principle of an AC generator?
EMI
What is the nature of equipotential surfaces for the case of an isolated positive charge?
Concentric spherical surfaces
For metals, what is the nature of the temperature coefficient of resistivity?
It is positive
A charged particle in an external magnetic field will take a circular path when ___________.
v is perpendicular to B
For a perfectly diamagnetic material, what is zero?
Susceptibility(χ)
If a current flows through a coil in the counterclockwise direction, that face of the coil becomes the _____ of the magnet.
What is the reason for the unavailability of cell phone signals inside an elevator?
Electrostatic Shielding
m2V-1s-1 is the SI unit of __________.
Electron mobility.
Parallel currents ____, and antiparallel currents _____
attract, repel
1. T m A–1
2. A m–1
3. A m2
1. Permeability
2. Magnetisation
3. Magnetic moment
What is called as back emf?
Self-induced emf
The electric field at a point due to an infinitely long sheet of charges is 0.75 N/C. What will be the magnitude of the field when the distance between the point and the sheet is doubled?
0.75 N/C
Describe the nature of the resistivity versus temperature graph for Nichrome.
They are linearly dependent
What must be the resistance in a circuit where a Galvanometer is converted into a Voltmeter?
Ig/(I-Ig) R
What does not exist as a consequence of Gauss's Law in Magnetism?
A magnetic monopole
A closed loop moves normal to the constant electric field between the plates of a large capacitor. Is a current induced in the loop (i) when it is wholly inside the region between the capacitor plates (ii) when it is partially outside the plates of the capacitor? The electric field is normal to the plane of the loop.
Changing electric flux does not induce emf
Obtain the work done in bringing a charge of 2×10–9 C from infinity to the point P. A charge of 4 × 10–7C is located 9 cm away from point P.
8 × 10–5 J
Two wires of A and B are made of the same material. A is twice as long as B and has a diameter 3 times that of B. If resistance in A = 4Ω, what is the resistance of B?
18Ω
What is the magnitude of force on an electron moving with a velocity of 0.5 x 107 m/s in a magnetic field of strength 0.5 x 10-2 T making an angle 30° with respect to the field?
0.2 x 10-14 N
A plane electromagnetic wave of frequency 25 MHz travels in free space along the x-direction. At a particular point in space and time, E = 6.3 V/m. What is B at this point?
0.021 μT
A pair of adjacent coils has a mutual inductance of 1.5 H. If the current in one coil changes from 0 to 20 A in 0.5 s, what is the change of flux linkage with the other coil?
30 Wb