Answer:
The correct answer will be-
1. Allows scientists to replicate experiments
2. Tests only one variable at a time
3. Plans how to record data so they can be published
Explanation:
A scientific experiment is performed to test the hypothesis which represents the limited explanation of the phenomenon.
The experiment is designed in a way that it test one variable at a time like the growth of plants. The experiment must be designed in a way that it can be replicated to reduce the error and repeated by other scientific persons to support the experiment. The design includes the plan for recording the results as it is one of the steps of the scientific method.
Thus, the selected options are the correct answer.
Controlled experiment is the type of experiment that involves changing only one variable at a time. Controlled experiment is subtly defined as an experiment which holds everything constant except one particular variable. This type of experiment allows only one variable to ever change at a given time
Answer:
(A) 12.222 ohm (B) 990 W
Explanation:
We have given the voltage of the heating element V = 110 V
The current in the heating element i = 9 A
(a) According to ohm's law V =iR
So 
(b) The power dissipated in the resistor is given by 
So the power dissipated = 990 W
Answer:
The two main reasons that your results might not match up each time are uncontrolled conditions and experimental error.
An educated guess is a “hypothesis”
