Physics Past Questions and Answers

In a slide wire bridge, the balance is obtained at a point 25cm from one end of wire 1m long. The resistance to be tested is connected to that end and a standard resistance of 3.6\(\Omega\) is connected to the other end of the wire. Determine the value of the unknown resistance

A 3.2\(\Omega\)
B 1.4\(\Omega\)
C 3.21\(\Omega\)
D 1.2\(\Omega\)

Question 2102:

Electrons were discovered by

A Dalton
B James Charwick
C J.J. Thompson
D Niels Bohr

Question 2103:

Which of the following is/are the limitations to the Rutherford's atomic models?
I. It is applicable when energy is radiated as electrons are revolving
II. It is applicable when energy is radiated in a continuous mode
III. It is applicable to an atom with only one electron in the other shell

A I only
B II only
C I & II only
D I, II & III only

Question 2104:

Which of the following equations is the correct definition of the reactance of an indicator L?

A Reactance = (Amplitude of voltage) \(\div\) (Amplitude of current)
B Reactance = (Amplitude of voltage) x (Amplitude of current)
C Reactance = (Amplitude of current)\(^2\) \(\div\) (Amplitude of voltage)
D Reactance = (Amplitude of current)\(^2\) \(\div\) (Amplitude of voltage)\(\frac{1}{2}\)

Question 2105:

Ripple in a power supply unit is caused by

A Using an alternating current source
B Forward voltage drop
C Heavy load
D Using a zener diode