national physical laboratory Recruitment Process, Interview Questions & Answers

Q: 9 cards are there. You have to arrange them in a 3*3 matrix. Cards are of 4 colors. They are red, yellow, blue and green. Conditions for arrangement: one red card must be in first row or second row. 2 green cards should be in 3rd column. Yellow cards must be in the 3 corners only. Two blue cards must be in the 2nd row. At least one green card in each row.

Q: A rich man died. In his will, he has divided his gold coins among his 5 sons, 5 daughters and a manager. According to his will: First give one coin to manager. 1/5th of the remaining to the elder son.Now give one coin to the manager and 1/5th of the remaining to second son and so on..... After giving coins to 5th son, divided the remaining coins among five daughters equally.All should get full coins. Find the minimum number of coins he has?

Q: There are two balls touching each other circumferencically. The radius of the big ball is 4 times the diameter of the small all. The outer small ball rotates in anticlockwise direction circumferencically over the bigger one at the rate of 16 rev/sec. The bigger wheel also rotates anticlockwise at N rev/sec. What is 'N' for the horizontal line from the centre of small wheel always is horizontal.

Q: T, U, V are 3 friends digging groups in fields. If T & U can complete i groove in 4 days &, U & V can complete 1 groove in 3 days & V & T can complete in 2 days. Find how many days each takes to complete 1 groove individually.

Q: There are 3 sticks placed at right angles to each other and a sphere is placed between the sticks . Now another sphere is placed in the gap between the sticks and Larger sphere . Find the radius of smaller sphere in terms of radius of larger sphere.

Q: ABCDE are sisters. Each of them gives 4 gifts and each receives 4 gifts No two sisters give the same combination ( e.g. if A gives 4 gifts to B then no other sisters can give four to other one.) (i) B gives four to A.(ii) C gives 3 to E. How much did A,B,C,E give to D?

Q: There is a room with a door (closed) and three light bulbs. Outside the room there are three switches, connected to the bulbs. You may manipulate the switches as you wish, but once you open the door you can't change them. Identify each switch with its bulb.

Q: Every day a cyclist meets a train at a particular crossing .The road is straight before the crossing and both are travelling in the same direction.Cyclist travels with a speed of 10 kmph.One day the cyclist come late by 25 minutes and meets the train 5 km before the crossing.What is the speed of the train?

Q: A vessel is full of liquid. From the vessel, 1/3rd of the liquid evaporates on the first day. On the second day 3/4th of the remaining liquid evaporates. What fraction of the volume is present at the end of the second day

Q: Jarius and Kylar are playing the game. If Jarius wins, then he wins twice as many games as Kylar. If Jarius loses, then Kylar wins as the same number of games that Jarius wins. How many do Jarius and Kylar play before this match?

Q: In a Park, N persons stand on the circumference of a circle at distinct points. Each possible pair of persons, not standing next to each other, sings a two-minute song ? one pair immediately after the other. If the total time taken for singing is 28 minutes, what is N?

Q: Give two dice - one is a standard dice, the other is blank (nothing painted on any of the faces). The problem is to paint the blank dice in such a manner so that when you roll both of them together, the sum of both the faces should lie between 1 and 12. Numbers from 1-12 (both inclusive) equally likely.

Q: Given a collection of points P in the plane , a 1-set is a point in P that can be separated from the rest by a line, .i.e the point lies on one side of the line while the others lie on the other side. The number of 1-sets of P is denoted by n1(P)....

Q: Consider a series in which 8 teams are participating. each team plays twice with all other teams. 4 of them will go to the semi final. How many matches should a team win, so that it will ensure that it will go to semi finals.?

Q: In a country where everyone wants a boy, each family continues having babies till they have a boy. After some time, what is the proportion of boys to girls in the country? (Assuming probability of having a boy or a girl is the same)

Q: A Man is sitting in the last coach of train could not find a seat, so he starts walking to the front coach ,he walks for 5 min and reaches front coach. Not finding a seat he walks back to last coach and when he reaches there,train had completed 5 miles. what is the speed of the train ?

Q: A person meets a train at a railway station coming daily at a particular time. One day he is late by 25 minutes, and he meets the train 5 k.m. before the station. If his speed is 12 kmph, what is the speed of the train.

Q: Joe started from Bombay towards Pune and her friend julie in opposite direction. they met at a point . distance traveled by joe was 1.8 miles more than that of julie.after spending some both started there way. joe reaches in 2 hours while julie in 3.5 hours.Assuming both were traveling with constant speed. What is the distance between the two cities.

Q: There are some chickens in a poultry. They are fed with corn. One sack of corn will come for 9 days. The farmer decides to sell some chickens and wanted to hold 12 chicken with him. He cuts the feed by 10% and sack of corn comes for 30...

Q: In mathematics country 1,2,3,4....,8,9 are nine cities. Cities which form a no. that is divisible by 3 are connected by air planes. (e.g. cities 1 & 2 form no. 12 which divisible by 3 then 1 is connected to city 2). Find the total no. of ways you can go to 8 if you are allowed to break the journeys.