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Find current and voltage across resistors R1 and R2, when they connected in parallel and in series. A 12V battery is connected, R1=4Ω and R2=3Ω.

First of all, we try to find a circuit where resistors are connected in parallel. When resistors are connected in parallel, the voltage across each resistor is exactly the same, V1 = V2 = 12 V. On the other ...
EA
Answered by Egle A. • Physics tutor
38690 Views

A ball is dropped from rest at a height of 2 metres. Assuming acceleration due to gravity (g) is 10m/s^2 calculate the velocity of the ball just before it hits the floor.

Using the equation V 2 = U 2 + 2 a s, where V = final velocity, U = initial velocity, a = acceleration, s = displacement, we can substitute in the values given in the question to calculate the final velocity...
PB
Answered by Phil B. • Physics tutor
2642 Views

When a particle travels in a circle of radius r, at constant speed v, what is its acceleration

v 2 /r, towards the center of the circle.Remember that acceleration is the rate of change of velocity , not merely of speed. This means that the change in direction is important. In a unit of time, the veloc...
Answered by • Physics tutor
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Two current carrying wires are placed next to each other and anti-parallel currents are allowed to flow. Is the magnetic force between the wires attractive or repulsive?

Consider the first wire on the left with current running up (arbitrary choice). By the 1st right hand rule, the magnetic field anywhere on the right will be into the page. By the 2nd right hand rule, the for...
Answered by • Physics tutor
2124 Views

This is a question on the photoelectric effect: For potassium, the work function is 3.65E-19J. Find the maximum wavelength of light that will cause photoelectrons to be emitted when shone onto potassium.

We know thatphoton energy = minimum energy needed to free an electron + max kinetic energy of emitted photoelectronAs we have been asked for the maximum wavelength , we know these photoelectrons just have en...
KB
Answered by kathryn b. • Physics tutor
3203 Views