Answer:
1) current = I
2) Resistance = V/I
3) current = 2I
4) resistance = V/2I
5) current = 3I
6) Resistance = V/3I
7) Current = 4I
8) Resistance = V/4I
Explanation:
When one bulb is connected across the battery then let say the current is given as I
Then resistance is given as

When two bulbs are in parallel with the battery then
total current becomes twice of initial current
so we have
current = 2I
Resistance of the circuit is now

When three bulbs are in parallel with the battery then
total current becomes three times of initial current
so we have
current = 3I
Resistance of the circuit is now

When four bulbs are in parallel with the battery then
total current becomes four times of initial current
so we have
current = 4I
Resistance of the circuit is now

Explanation:
Given that,
Mass of Nichrome, m = 0.5 g
The resistance of the wire, R = 0.673 ohms
Resistivity of the nichrome wire, 
Density, 
(A) The length of the wire is given by using the definition of resistance as :
Volume,

Area,
....(1)

(b) Equation (1) becomes :

Hence, this is the required solution.
Answer:
The pressure on the floor is 12 Pascal(Pa).
Explanation:
Given,
Force (F) = 240N
Area (A) = 20 cm^2
Pressure (P) = ?
we know that,
P = F/A
= 240/ 20
= 12 Pa
Answer:
yes it does exert a force, it pushes it up
Explanation:
this is called normal force
if it didn't exert a force the book would keep going down
according to newton every force has an equal amd opposite reaction
so the book exerts a force on the table and vice versa
hope this helped