A particle A of mass m and intial velocity v collides with a particle B of mass $\frac{m}{2}$ which is at rest. The collision is head on, and elastic. The ratio of the de-Broglie wavelengths λA to λB after the collision is 

A) $\frac{\lambda_{A}}{\lambda_{B}}=2$

B) $\frac{\lambda_{A}}{\lambda_{B}}=\frac{2}{3}$

C) $\frac{\lambda_{A}}{\lambda_{B}}=\frac{1}{2}$

D) $\frac{\lambda_{A}}{\lambda_{B}}=\frac{1}{3}$


A man grows into a giant such that his linear dimensions increase by a factor of 9. Assuming that this density remains the same, the stress in the leg will change by a factor of

A) $\frac{1}{9}$

B) 81

C) $\frac{1}{81}$

D) 9


A magnetic needle of magnetic moment 6.7 × 10-2 Amand moment of inertia 7.5 × 10-6 kg  m2 is performing simple harmonic oscillations in a magnetic field of 0.01 T. Time taken for 10 complete oscillations is

A) 8.89 s

B) 6.98 s

C) 8.76 s

D) 6.65 s


A time-dependent force F =6t acts on a particle of mass 1 kg. If the particle starts from rest, the work done by the force during the first 1 s will be 

A) 22J

B) 9 J

C) 18 J

D) 4.5 J


When a current of 5 mA is passed through a galvanometer having a coil of resistance 15Ω, it shows full-scale deflection. The value of the resistance to be put in series with the galvanometer  to convert it into a voltmeter of range 0-10 V is

A) $2.045 \times 10^{3}$O

B) $2.535 \times 10^{3}$O

C) $4.005 \times 10^{3}$O

D) $1985 \times 10^{3}$O