1. In a pulsed radar, the transmitted pulses are of high frequency
2. In a pulsed radar, the transmitted pulses are of high power
3. In a pulsed radar, the transmitted pulses are of brief duration
4. In a pulsed radar, the transmitted pulses are of square wave shape.

1. The expressions are scanned from left to right.
2. The operations are scanned in the order NOT, AND, OR.
3. All operators (i.e., NOT, AND and OR) are scanned together.
4. In one scanning all the operators of only one type are scanned.

Assertion (A): The resistance of a copper specimen changes by about 22% when temperature is increased from room temperature to 700°C.

Reason (R): The physical properties of a material are determined mostly by the extent of impurities.

Assertion (A): Impatt diode is an avalanche diode.

Reason (R): Avalanche breakdown phenomenon occurs when a p-n junction is reverse biased.

Match the following:

1. A file is a data structure which consists of a sequence of components of the same type.
2. The number of components in a file is variable.
3. The components in a file can be accessed only sequentially starting from the beginning of the file.