# The product of generalized coordinate and its conjugate momentum has the dimension of

1. force
2. energy
3. linear momentum
4. angular momentum

# The generalized momentum px of a particle of mass m with velocity vx in an electromagnetic field is given by

1. px = mvx + qAx
2. px = mvx – qAx
3. qvxA
4. mvx
5. none of the above

# The dimensions of generalized momentum

1. are always those of linear momentum
2. are always those of angular momentum
3. may be those of linear momentum
4. may be those of angular momentum
5. both C and D

# Whenever the Lagrangian for a system does not contain a coordinate explicitly

1. $\dpi{120}&space;\fn_jvn&space;q_{k}$ is cyclic coordinate
2. $\dpi{120}&space;\fn_jvn&space;p_{k}$ is cyclic coordinate
3. $\dpi{120}&space;\fn_jvn&space;p_{k}$ the generalized momentum is a constant of motion
4. $\dpi{120}&space;\fn_jvn&space;q_{k}$ is always zero
5. both A and C

# The energy gap in a semiconductor is

1. Equal to insulator
2. Less than an insulator
3. More than an insulator
4. None of these

# A lens of focal length 20 cm has a power of

1. 0.20 diopters
2. 5 diopters
3. 10 diopters
4. 50 diopters

1. Zero
2. evB
3. ILB