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The velocity of a particle is zero at time t= 2 , then 

(A) acceleration must be zero at t= 2 

(B) displacement must be zero in the interval t = 0 to t = 2. 

(C) acceleration may be zero at t= 2 

(D) velocity must be zero for t> 2 

The addition of Br₂ to (E) – but – 2 – ene gives 

(A) (R, R) 2 – 3- dibromobutane 

(B) (S, S) – 2 – 3 – dibromobutane 

(C) (R, S) – 2 – 3 – dibromobutane 

(D) a mixture of (R, R) and (S, S) 2, 3 dibromobutane 

Among the following compounds of Boron, the species which also forms π– bond in addition to σ- bonds is :

(A) BF^–₄

(B) BH₃

(C) B₂H₆

(D) BF₃

The population inversion in helium-neon laser is produced by 

(a) photon excitation 

(b) chemical reaction 

(c) inelastic atomic collision 

(d) electron excitation 

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

The point of inflection of the function 

y = ∫(t² – 3t + 2)dt   x ∈[0,x] is :

(A)  (1/2, 3/2)

(B)  (3/2, 3/4)

(C)  (-3/2, -3/4)

(D)  (-1/2, – 3/2)

A train travels east towards Hubli at 80 km/hr. A man on the train runs from the front of the train toward the rear of the train at 10 km/hr with respect to train. As he runs, he carries a plate of fruit with him. He notices a giant spider on the plate and throws the plate away from him (toward the rear of the train) at 20 km/hr with respect to him. Just after that instant, the startled spider jumps towards the man at 5 km/hr with respect to plate. The instant after the spider jumps toward the man, how fast is the spider approaching Hubli?

(A) 45km/hr 

(B) 115 km/hr 

(C) 55 km/hr 

(D) 95 km/hr

The number of solutions of the system of equations 2x + y – z = 7, x – 3y + 2z = 1 and x + 4y – 3z = 5 is

(a) 0 

(b) 1

(c) 2 

(d) 3

The basic idea of MASER was first given by 

(A) Max Planck 

(B) Einstein 

(C) Townes 

(D) Fresnel

For given LR circuit, growth of current as function of time t is shown in graph. Which of the following option represents value of time constant most closely for the circuit?

(A) 0.4 s 

(B) 0.7 s 

(C) 1 s 

(D) 2.4 s