A 10gm bullet moving directly upward at 1000 m/s strikes and passes through the center of mass of a 10 kg block initially at rest .The bullet emerges from the block moving directly upward at 400 m/s. What will be velocity of the block just after the bullet comes out of it ?

(A) 0.6 m/s 

(B) 1 m/s 

(C) 0.4 m/s 

(D) 1.4 m/s

Cordite is a mixture of 

(A) nitroglycerine, guncotton and vaseline 

(B) borax, glycerine 

(C) carborundum and charcoal 

(D) glycerol and KMnO₄

Some pairs of ions are given below. In which pair, first ion is more stable than second ion ?

Which of these materials requires the least value of magnetic field strength to magnetize it? 

(A) Nickel 

(B) Silver 

(C) Tungsten 

(D) Sodium Chloride

Which of the following is a lyophobic colloid : 

(A) Gelatin 

(B) Sulphur 

(C) Starch 

(D) Gum Arabica 

Permanent magnet has properties retentivity and coercivity respectively, 

(a) low-low 

(b) high-high 

(c) high-low 

(d) low-high

Two circular coils can be arranged in any of the three following situations as shown in figure. Their mutual inductance will be

(a) maximum (B) 

(b) maximum (A) 

(c) maximum (C) 

(d) same in ail conditions

A circular disc of radius R rolls without slipping along the horizontal surface with constant velocity v₀. We consider a point A on the surface of the disc. Then, the acceleration of the point A is 

(a) constant in magnitude 

(b) constant in direction 

(c) constant in magnitude as well as direction 

(d) None of the above

Considering entropy(s) as a thermodynamic parameter, the criterion for the spontaneity of any process the change in entropy is :

(A) (ΔS _system – ΔS _surrounding) > 0

(B) ΔS _system  > 0 only

(C) ΔS _surrounding > 0 only

(D) (ΔS _system + ΔS _surrounding ) >0

If the line x + 2ky + 3 = 0 is a diameter of the circle x² + y² – 6x + 2y = 0, then k is equal to

(a) 3 

(b) -5

(c) -1 

(d) 5