Answer:
vi) Double the current in the wire, and double the number of turns in the 20-cm long solenoid
Explanation:
The magnetic field inside the solenoid and the current flowing in the coil of solenoid are related to each other by the following equation
B₀=μ₀nI₀
Where,
B₀ is the magnetic field in the middle of solenoid
n is the number of turns in the coil of solenoid
I₀ is the current flowing in the coil of solenoid
In the above equation, as μ₀ is a constant so the magnetic field will be directly proportional to the number of turns multiplied by the current. So, changing the radius of the coil or length of the coil will have no effect on the magnetic field.
As we have to increase the magnetic field by 4 times, we need to double the current as well as the number of turns as mentioned in the option vi.
Answer: 3P/2
Explanation: Let the resistance of the bulbs be R.
now lets consider a Voltage V is supplied to the parallel circuit such that

V=IR
both single bulb( bulb 3) and the two bulbs ( bulb 1 and bulb 2) are provided the same Voltage
( as the voltage remains same in parallel circuit)
we can calculate the Current across both circuits
At Bulb 3
Current 1=V/R
Power1=Voltage * Current1
Power1=V*V/R
Power1=P
At Bulb 1 and Bulb 2
Total Resistance= R+R=2R

Power2=Voltage * Current2


Answer:
<h3>The answer is 8.91 m/s²</h3>
Explanation:
The acceleration of an object given it's mass and the force acting on it can be found by using the formula

f is the force
m is the mass
From the question we have

We have the final answer as
<h3>8.91 m/s²</h3>
Hope this helps you
Answer:
f = 8 %
Explanation:
given,
density of body of fish = 1080 kg/m³
density of air = 1.2 Kg/m³
density of water = 1000 kg/m²
to protect the fish from sinking volume should increased by the factor f
density of fish + density of water x increase factor = volume changes in water
1080 +f x 1.2 =(1 + f ) x 1000
1080 + f x 1.2 = 1000 + 1000 f
998.8 f = 80
f = 0.0800
f = 8 %
the volume increase factor of fish will be equal to f = 8 %