Answer:
Explanation:
Electric field due to a point charge Q at a point at distance d is given by the relation
E = 
Since Q1 and Q2 are of the same magnitude and distance , so they will create eletric field of same magnitude. Similarly field due to rest of the charges will also be same.
The charges are situated on the corners of a square in such a way that
equal charges of Q1 and Q3 are situated on the diametrically opposite corners of the square. Fields due to these two charges will be equal and opposite in direction. Therefore net field due to these two charges will be zero.
On the same ground, we can say that field due to Q2 and Q4 at the centre will be equal and opposite and therefore they will cancel out each other. Net field at the centre will be zero
Overall, net field due to all the four charges will be zero
Answer: Photoelectric wave
Explanation: Because it represents an interaction between light and matter that describes light as an electromagnetic wave.
<span>D. sugar changes from white to a light amber color
We're looking for a chemical change. So let's examine the options and see what happening with them.
A. adding cream and milk to the mixture
She's just making a mixture here. No unexpected reactions or changes happen as she adds the cream and milk. So this is the wrong answer.
B. mixing the sugar with water
Dissolving the sugar in water. Once again, nothing unusual happens and if she were to evaporate the water, she'd be left with the original sugar. So this is the wrong answer.
C. melting the sugar
Just starting a simple phase change. Once again, no the right answer.
D. sugar changes from white to a light amber color
She's melted the sugar and has a clear fluid. As she continued to heat this fluid, it suddenly turns light amber. She has made a permanent change to the substance that she can't undo by simply physical means. She has converted part of the sugar into caramel. So a chemical change has happened here.</span>
Answer:
5.634 N rightwards
Explanation:
qo = - 3 x 10^-7 C
q1 = - 9 x 10^-6 C
q2 = 10 x 10^-6 C
r1 = 7 cm = 0.07 m
r2 = 20 cm = 0.2 m
The force on test charge due to q1 is F1 which is acting towards right
According to the Coulomb's law

F1 = (9 x 10^9 x 9 x 10^-6 x 3 x 10^-7) / (0.07 x 0.07)
F1 = 4.959 N rightwards
The force on test charge due to q2 is F1 which is acting towards right
According to the Coulomb's law

F2 = (9 x 10^9 x 10 x 10^-6 x 3 x 10^-7) / (0.2 x 0.2)
F2 = 0.675 N rightwards
Net force on the test charge
F = F1 + F2 = 4.959 + 0.675 = 5.634 N rightwards
Answer:
True.
Explanation:
The velocity vector is constant in magnitude but changing in direction. Because the speed is constant for such a motion, many students have the misconception that there is no acceleration. ... But the fact is that an accelerating object is an object that is changing its velocity.