GCSE Physics Question Analysis Topic: Physics - Short Questions
Exam Questions:
1) A conducting loop is held above a current carrying wire 'PQ' as shown in the figure. Depict the direction of the current induced in the loop when the current in the wire PQ is constantly increasing.
2) A biconvex lens made of a transparent material of refractive index 1.25 is immersed in water of refractive index 1.33. Will the lens behave as a converging or a diverging lens? Give reason.
Answers:
For GCSE Physics, you should know:
1) Due to the PQ inside the coil, the magnetic field lines move in the direction into the plane of paper. Since the current constantly increases, so does the flux. Now according to Lenz's law, current will flow in the loop in such direction that opposes the magnetic flux through the loop that increases.
As such, the magnetic field should be projected outside the paper, and current should thus flow anti-clockwise (right-hand rule).
2) First, let's jot down each of the materials' refractive index.
Water: 1.33
Transparent material: 1.25
Since the refractive index of water is higher than that of the transparent material, the biconvex lens thus behaves as a diverging lens.
Work hard for your GCSE Physics examination!
End of analysis. Great!