NORTHRIDGE PSY 150 PSYCHOLOGY EXAM
WITH ACTUAL QUESTIONS AND VERIFIED
ANSWERS, PLUS EXPLAINED
RATIONALES/EXPERT VERIFIED FOR
GUARANTEED 100% PASS 2026/LATEST
UPDATE/INSTANT DOWNLOAD PDF
1. A researcher wants to determine whether exposure to violent
media causes an increase in aggressive behavior. Participants are
randomly assigned to watch either violent or nonviolent content
and are subsequently placed in a situation where their aggressive
behavior can be measured. Which feature of this study is most
important for allowing the researcher to make a causal conclusion?
A. The participants completed a personality questionnaire
B. The researcher used random assignment to conditions
C. The study included a large number of participants
D. The participants knew the purpose of the study
Answer: B. The researcher used random assignment to conditions
Rationale: Random assignment is critical because it helps distribute
preexisting participant characteristics across experimental groups.
When the independent variable is manipulated and participants are
randomly assigned, differences in the dependent variable can more
confidently be attributed to the manipulation rather than to preexisting
differences. A large sample improves precision, but by itself does not
establish causation.
1
, 2. A psychologist measures the relationship between hours of sleep
per night and scores on a concentration test. The correlation is
−0.78. Which interpretation is most accurate?
A. People who sleep more always perform worse
B. Sleep causes concentration scores to decrease
C. There is a strong negative association between sleep duration and
concentration scores
D. There is no meaningful relationship between the variables
Answer: C. There is a strong negative association between sleep
duration and concentration scores
Rationale: A correlation of −0.78 represents a relatively strong
negative relationship: as one variable increases, the other tends to
decrease. However, correlation does not establish causation. The
researcher cannot conclude from this result alone that sleep causes
concentration to decrease.
3. A professor wants to study whether stress affects memory.
Students are randomly assigned to either a high-stress condition or
a low-stress condition before completing a memory test. In this
experiment, what is the dependent variable?
A. Stress condition
B. Assignment procedure
C. Memory-test performance
D. Student age
Answer: C. Memory-test performance
Rationale: The dependent variable is the outcome that researchers
measure to determine whether it changes as a result of the
independent variable. Here, stress condition is manipulated, while
memory performance is measured. Therefore, memory-test
performance is the dependent variable.
2
, 4. Which statement best illustrates the difference between a
hypothesis and a theory in psychological science?
A. A hypothesis is always correct, whereas a theory is sometimes
incorrect
B. A hypothesis is a testable prediction, whereas a theory is a broader
explanatory framework supported by evidence
C. A hypothesis is based on opinion, whereas a theory is based on
intuition
D. A theory can never be tested experimentally
Answer: B. A hypothesis is a testable prediction, whereas a theory is
a broader explanatory framework supported by evidence
Rationale: A hypothesis is a specific, testable prediction about
relationships between variables. A theory is a broader system of
interconnected explanations that organizes evidence and generates
hypotheses. Scientific theories are not simply guesses; they are
supported by substantial evidence and remain open to revision.
5. A researcher repeats a previously published experiment using the
same basic procedures but with a new group of participants. What
scientific practice is being demonstrated?
A. Random sampling
B. Replication
C. Placebo administration
D. Operationalization
Answer: B. Replication
Rationale: Replication involves repeating a study or investigation to
determine whether similar findings can be obtained again. Replication
is essential because a single study may produce unusual results due to
sampling problems, measurement issues, or chance.
3
, 6. A psychologist defines “academic stress” as the score obtained by
participants on a 20-item academic-stress questionnaire. This
definition is an example of:
A. A confounding variable
B. An operational definition
C. Random assignment
D. A dependent hypothesis
Answer: B. An operational definition
Rationale: An operational definition explains precisely how an
abstract psychological concept will be measured or manipulated.
Because “academic stress” is defined using scores on a specific
questionnaire, the researcher has converted an abstract construct into
something measurable.
7. Which part of the neuron typically receives incoming information
from other neurons?
A. Axon
B. Myelin sheath
C. Dendrites
D. Terminal buttons
Answer: C. Dendrites
Rationale: Dendrites are branching structures that generally receive
signals from other neurons. The cell body integrates information, the
axon transmits electrical impulses away from the cell body, and
terminal buttons release neurotransmitters into the synapse.
8. A neuron remains at approximately −70 millivolts before receiving
sufficient stimulation to fire. This state is known as:
A. Resting potential
B. Refractory potential
4