581: For reproducing sound, a CD (Compact Disc) audio player uses a

(a) quartz crystal
(b) titanium needle
(c) laser beam
(d) barium titanate ceramic
582: Hawala transactions relate to payments

(a) received in rupees against overseas currencies and vice versa without going through the official channels

(b) received for sale/transfer of shares without going through the established stock exchanges

(c) received as commission for services rendered to overseas investors/buyers/ sellers in assisting them to get over the red tape
and/or in getting preferential treatment

(d) made to political parties or to individuals for meeting election expenses
583: A goat is tied to two poles P and Q with ropes that are 15-metre long. P and Q are 20-metre apart as shown in the given diagram:


584: Match List-I with List-II and select the correct answer using the code given below the lists:

List-I (Aluminium Company) : List-II (Location)

A. BALCO : 1. Hirakud
B. HINDALCO : 2. Korba
C. Indian Aluminium Company : 3. Koraput
D. NALCO : 4. Renukoot


(A) 2 1 4 3
(B) 3 1 4 2
(C) 2 4 1 3
(D) 3 4 1 2
585: What are Rubies and Sapphires chemically known as?

(a) Silicon dioxide

(b) Aluminium oxide

(c) Lead tetroxide

(d) Boron nitride