The brightness of the lamp is proportional to the current flowing through the lamp: the larger the current, the brighter the lamp.
The current flowing through the lamp is given by Ohm's law:

where
V is the potential difference across the lamp, which is equal to the emf of the battery, and R is the resistance of the lamp.
The problem says that the battery is replaced with one with lower emf. Looking at the formula, this means that V decreases: if we want to keep the same brightness, we need to keep I constant, therefore we need to decrease R, the resistance of the lamp.
Answer:
A. 3.4 m
Explanation:
Given the following data;
Force = 56.7N
Workdone = 195J
To find the distance
Workdone is given by the formula;
Making "distance" the subject of formula, we have;

Substituting into the equation, we have;

Distance = 3.4 meters.
Actually, the speed of the earth is the same everywhere, taking the angular speed as the valid measure of the speed