Kirchhoff's laws are applied to the circuit shown.
What is the equation for the dotted loop?
A travelling wave on the surface of a lake has wavelength . Two points along the wave oscillate with the phase difference of . What is the smallest possible distance between these two points?
The primary of an ideal transformer has 1000 turns and the secondary 100 turns. The current in the primary is 2 A and the input power to the primary is 12 W .
Which one of the following about the secondary current and the secondary power output is true?
secondary current | secondary power output | |
---|---|---|
A. | 20 A | 12 W |
B. | 0.2 A | 12 W |
C. | 0.2 A | 120 W |
D. | 20 A | 120 W |
An ion follows a circular path in a uniform magnetic field. Which single change decreases the radius of the path?
The graphs A to D below are plots of against in arbitrary units.
Which one of the graphs best represents the variation of , the electrostatic potential due to a positive point charge, with , the distance from the point charge?
P and Q are two opposite point charges. The force F acting on P due to Q and the electric field strength E at P are shown.
Which diagram shows the force on Q due to P and the electric field strength at Q?
How many different states can be represented by a 4-bit binary number?
The two graphs below represent the variation with distance, , for to of the electric field and the electric potential around an isolated point charge.
Graph 1:
Graph 2:
The work done by an external force in moving a test charge from to is equal to multiplied by the
In the circuit shown, the fixed resistor has a value of and the variable resistor can be varied between and .
The power supply has an emf of 12 V and negligible internal resistance. What is the difference between the maximum and minimum values of voltage across the resistor?
What is the unit of electrical energy in fundamental SI units?