## Physics It is more difficult to walk on ice than on a concrete road because

There is more friction between the ice and feer
There is very little friction between the ice and feet pressing it
Ice is soft when compared to concrete
None of these

Acceleration
Speed
Displacement
Jerk

## Physics When a vehicle passes, TV reception gets distorted. This is because

Spark plug creates electromagnetic disturbances
Vehicle pollution affects the performance of the TV components
Modern vehicles use electroignition system

## Physics The threshold frequency is the frequency below which :

Photo current decreases with voltage
Photo electric emission is not possible
Photo current increases with voltage
Photo current is constant

## Physics A photon of X-ray has energy of 1 keV. A photon of visible radiation has energy of 3 eV. In this context, which one of the following statements is not correct?

Both the photons have different energies.
The speeds of both the photons in vacuum are different
The wavelength of X-ray photon is less than the wavelength of visible radiation photon.
The frequency of X-ray photon is higher than the frequency of visible radiation photon.