Physics Past Questions and Answers

In which of the following activities is an induction coil not useful?

A Investigation of high voltages
B Study of electric discharge
C Operation of X-ray tubes
D A.C. power transmission

Question 1872:

In a series R-L-C circuit, R = 10\(\Omega\), \(X_{c}\)= 4\(\Omega\) and \(X_{L}\) = 9\(\Omega\). The impedance of the circuit is

A 4.1\(\Omega\)
B 5.0\(\Omega\)
C 10.8\(\Omega\)
D 11.2\(\Omega\)

Question 1873:

A student uses two compass needles to investigate the magnetic field around a bar magnet. Which of the following diagrams show the correct directions of the needles?

Question 1874:

Which of the following is emitted in a process of natural radioactivity?

A \(\alpha\)- particles and \(\beta\)- particles
B \(\alpha\)- particles and X-rays
C \(\beta\)- particles and X-rays
D \(\lambda\)- rays and X-rays

Question 1875:

In which of the following situations is photoelectric effect employed?
I. Automatic devices for switching on light at dusk
II. Automatic doors in departmental stores
III. Automatic devices for switching on air conditioners
IV. Automatic voltage stabilizers

A I, II and IV only
B I, III and IV only
C III and IV only
D I and II only