>>  >>  >>  >>

# IIT-JEE-Physics-Screening-2004

1.      White light is incident on the interface of glass and air as shown in the figure. If green light is just totally internally reflected then the emerging ray in air contains.

(a)       yellow, orange, red
(b)       violet, indigo, red
(c)       all colours
(d)       all colours except green

2.      Liquid oxygen at 50 K is heated to 300 K at constant pressure of 1 atm. The rate of heating is constant. Which of the following graphs represents the variation of temperature with time ?

3.      A ray of light is incident on an equilateral glass prism place on a horizontal table. For minimum deviation which of the following is true?

(a)       PQ is horizontal
(b)       QR is horizontal
(c)       RS is horizontal
(d)       Either PQ or RS is horizontal

4.      An ideal gas expands isothermally from a volume V1 to V2 and then compressed to original volume V1 adiabatically. Initial pressure is P1 and final pressure is P3. The total work done is W. Then

(a)       P3 > P1, W > 0
(b)       P3 < P1, W < 0
(c)       P3 > P1, W < 0
(d)       P3 = P1, W = 0

5.      A block P of mass m is placed on a frictionless horizontal surface. Another block Q of same mass is kept on P and connected to the wall with the help of a spring of spring constant k as shown in the figure. µs is the coefficient of friction between P and Q. The blocks move together performing SHM of amplitude A. The maximum value of the friction force between P and Q is

(a)       kA
(b)       kA/2
(c)       zero
(d)       µsmg

6.    After 280 days, the activity of a radioactive sample is 6000 dps. The activity reduces to 3000 dps after another 140 days. The initial activity of the sample in dps is
(a)       6000
(b)       9000
(c)       3000
(d)       24000