Answer:
Induced emf, 
Explanation:
Given that,
Length of the helicopter, l = 4 m
Angular speed of the helicopter, 
The vertical component of the Earth’s magnetic field is, 
We need to find the induced emf between the tip of a blade and the hub. The induced emf in terms of angular velocity of an rotating object is given by :
So, the induced emf between the tip of a blade and the hub is . Hence, this is the required solution.
Answer:
C. 0.25J
Explanation:
Energy stored in the magnetic field of the inductor is expressed as E = 1/2LI² where;
L is the inductance
I is the current flowing in the inductor
Given parameters
L = 20mH = 20×10^-3H
I = 5A
Required
Energy stored in the magnetic field.
E = 1/2 × 20×10^-3 × 5²
E = 1/2 × 20×10^-3 × 25
E = 10×10^-3 × 25
E = 0.01 × 25
E = 0.25Joules.
Hence the energy stored in the magnetic field of this inductor is 0.25Joules
Gamma rays have the highest energies and the shortest wavelengths.
Velocity is a speed AND a direction.
When you turn a corner, or go around a curve in the road, your
direction changes, but the reading on the dial doesn't change.
So it can't be showing velocity. It must be showing only speed.
That's probably a big part of the reason why it's called a speedometer
and not a velocimeter.
Answer: The correct answer is option (D).
Explanation:
Voltmeter is a device which measures the the voltage applied across the circuit. It is an electrical instrument used to measure the electric potential between the two points in an electric circuit.
Where as:
A switch is the device which used to connect or disconnect the circuit.
Resistor is a device which opposes the flow of current is an electric circuit.
An ammeter the is an electrical device which measures the amount of current in flowing in amperes in an electrical circuit
Hence,the correct answer is option (D).
