ability to store electrical charge.
ratio of charge stored to potential difference.
ratio of potential difference to charge stored.
ratio of work done to charged stored.
Eb. The energy stored by the capacitor is Ec.
What is the relationship between Eb and Ec?
Eb < Ec
Eb = Ec
Eb > Ec
The relationship depends on R.
Which of the following graphs shows how the induced emfε in the coil varies with t?
Scattering of alpha particles
What is the total capacitance of the combination?
Np turns and a secondary coil with Ns turns. The electrical power input to the primary is P. Which of the following is the power output from the secondary?
ms−1. The vertical component of the Earth’s magnetic field at the plane’s position is 10 μT.
What electromotive force (emf) is induced between points A and B on the aircraft?
(Vrms) 60 V.
What are the frequency of the ac power supply and the average power dissipated in the resistor?
I. Constructing the core from a solid block of steel.
II. Using large diameter wire in the coils.
III. Using wire of low resistivity.
Which of the above suggestions would reduce power loss?
II and III only
I, II and III
Which graph shows the variation with time t, of the induced emf ε in the coil as it moves from P to Q?
The uniform magnetic field is directed into the plane of the paper.
Which of the following is true for both the direction of the induced current in the sheet and the change in amplitude of the oscillations of the sheet with time?
Which loop(s) has/have the largest induced electromotive force (emf) at the instant when the loops enter the magnetic field?
Y and Z only
X and Y only
E0 and periodic time T. What are the peak emf and periodic time when the frequency of rotation is doubled?
What is the total capacitance?
What is the direction of the induced currents in loop B and loop C?
for a transformer is 2.5.
The primary coil of the transformer draws a current of 0.25 A from a 200 V alternating current (ac) supply. The current in the secondary coil is 0.5 A. What is the efficiency of the transformer?
The resistance of the coil is 5.0 Ω
. Which of the following is the average power dissipated in the loop?
What is the magnetic flux linkage?
The induced current in the straight piece of wire is
from P to Q.
from Q to P.
the change of magnetic flux density.
the change of magnetic flux linkage.
the rate of change of magnetic flux density.
the rate of change of magnetic flux linkage.
What is the magnitude of the induced emf?
What is the total capacitance of the arrangement?
I. the power output exceeds the power input
II. the magnetic flux produced by the primary coil entirely links the secondary coil
III. there are more turns on the secondary coil than on the primary coil.
Which of the above statements must be true?
I and II only
I and III only
Which of the following gives the correct times at which the magnitude of the magnetic flux linkage and the magnitude of the current in the loop are maximum?
Compared to end Q, end P will have
What is the power required to move the rod?
charge stored by the device.
energy stored by the device.
charge stored by the device for a potential difference of 1V across the device.
energy stored by the device for a potential difference of 1V across the device.
104 electrons are ejected from the pixel. The magnitude of the change in potential of the pixel is
Using thinner wires for the windings.
Using a solid core instead of a laminated core.
Using a core made of steel instead of iron.
Linking more flux from the primary to the secondary core.
The resistance of each resistor is R and the peak voltage of the ac supply is V0. Which of the following is the average power dissipated in the circuit?
The magnitude of the emf induced across the ends of the coil is maximum at time(s)
t1 and t3.
t2 and t4.
The energy stored in the capacitor is 4 J and the electric field in between the plates is 100 N C–1. The distance between the plates of the capacitor is doubled. What are the energy stored and the electric field strength?