Physics Past Questions and Answers

In the electrical method of magnetisation, the polarity of the magnet depends on the

A Amount of current passed
B Direction of current
C Magnetic material used
D Size of the magnetic material
E Orientation of the magnetic material in space

Question 2822:

A cell of e.m.f. 1.5v is connected in series with a resistor of 3\(\Omega\). A high resistance voltmeter connected across the cell registers only 0.9v. Calculate the internal resistance of the cell

A 5.0\(\Omega\)
B 4.5\(\Omega\)
C 2.4\(\Omega\)
D 2.0\(\Omega\)
E 1.8\(\Omega\)

Question 2823:

Calculate the resistance of the filament of lamp rated at 240V 60W

A 240\(\Omega\)
B 360\(\Omega\)
C 960\(\Omega\)
D 144\(\Omega\)
E 2880\(\Omega\)

Question 2824:

The diagram above illustrates a freely suspended bar magnet NS hanging from a point in a horizontal ceiling. The thread used for suspending the magnet and the axis of the magnet are as indicated on the diagram. The angle marked \(\theta\) is called the angle os

A Depression
B Declination
C Variation
D Elevation
E Dip

Question 2825:

Lenz's law of electromagnet states that

A The induced charge is constant for a fixed change of force
B A force is exerted on a current-carrying conductor in a magnetic field
C The magnitude of the induced e.m.f in a circuit is proportional to the rate of change of the number of lines of force linking the circuit
D The induced current in a conductor is in such a direction as to oppose the change producing it
E E.m.f. is induced in a circuit whenever there is a change in the magnetic flux linked with the circuit