Tag Archives: NEET

For a plane electromagnetic wave propagating in x-direction ….

For a plane electromagnetic wave propagating in x-direction, which one of the following combination gives the correct possible directions for electric field (E) and magnetic field (B) respectively?

(1) $\hat j + \hat k, \hat j + \hat k $
(2) $-\hat j + \hat k, -\hat j – \hat k $
(3) $\hat j + \hat k, -\hat j – \hat k $
(4) $-\hat j + \hat k,-\hat j+\hat k $ Continue reading For a plane electromagnetic wave propagating in x-direction ….

A small block slides down on a smooth inclined plane ….

A small block slides down on a smooth inclined plane, starting from rest at time t = 0. Let $S_n$ be the distance travelled by the block in the interval t = n-1 to t = n. Then, the ratio $\frac {S_n}{S_{n+1}}$ is:

(1) $\frac {2n-1}{2n}$
(2) $\frac {2n-1}{2n+1}$
(3) $\frac {2n+1}{2n-1}$
(4) $\frac {2n}{2n-1}$ Continue reading A small block slides down on a smooth inclined plane ….

A particle is released from height H above the ground ….

A particle is released from height H above the ground. At a certain instant its kinetic energy is three times its potential energy. The height h above the ground and the speed of the particle v at that instant are respectively:

(1) $\frac {H}{4},\frac {3gH}{2}$
(2) $\frac {H}{4},\frac {\sqrt {3gH}}{2}$
(3) $\frac {H}{2},\frac {\sqrt {3gH}}{2}$
(4) $\frac {H}{4},\sqrt {\frac {3gH}{2}}$ Continue reading A particle is released from height H above the ground ….

A radioactive nucleus ${}_Z^AX$ undergoes ….

A radioactive nucleus ${}_Z^AX$ undergoes spontaneous decay in the sequence ${}_Z^AX \to {}_{Z – 1}B \to {}_{Z – 3}C \to {}_{Z – 2}D$ where Z is the atomic number of element X. The possible decay particles in the sequence are:

(1) $\alpha,\beta^-.\beta^+$
(2) $\alpha,\beta^+,\beta^-$
(3) $\beta^+,\alpha,\beta^-$
(4) $\beta^-,\alpha,\beta^+$ Continue reading A radioactive nucleus ${}_Z^AX$ undergoes ….