Answer:
η = 40 %
Explanation:
Given that
Qa ,Heat addition= 1000 J
Qr,Heat rejection= 600 J
Work done ,W= 400 J
We know that ,efficiency of a engine given as

Now by putting the values in the above equation ,then we get

η = 0.4
The efficiency in percentage is given as
η = 0.4 x 100 %
η = 40 %
Therefore the answer will be 40%.
Answer:
The magnitude of the applied torque is 
(e) is correct option.
Explanation:
Given that,
Mass of object = 3 kg
Radius of gyration = 0.2 m
Angular acceleration = 0.5 rad/s²
We need to calculate the applied torque
Using formula of torque

Here, I = mk²

Put the value into the formula



Hence, The magnitude of the applied torque is 
The question is looking for "ellipse" and "two" to fill in the blanks.
Work= force x distance
work= 750 x 2
work =1500
power =work/time
power= 1500/ 0.3
power= 5000W
answer: b. 5000W