CIE Physics Paper-1: Specimen Questions 99 - 100 of 109
Question number: 99
The circuit shown contains four lamps and three switches.
Which switches must be closed to light only lamps 1 and 3?
switch S1 and switch S2 only
switch S1 and switch S3 only
switch S2 and switch S3 only
switch S1 only
For light only lamp 1 and 3 switch S1 must be closed. As figure shows only switch S1 is must be close for completing the circuit for lamp 1 and lamp 3.
Question number: 100
A straight wire carrying a current produces a magnetic field. Which diagram shows the correct shape of the field?
Magnetic field lines due to straight wire carrying current is always circular and the direction of the magnetic field line is given by right hand rules which is explained as follow,
The direction of the magnetic field is perpendicular to the wire and is in the direction the fingers of your right hand would curl if you wrapped them around the wire with your thumb in the direction of the current.