Defendant assigns as error the denial of its motion for a directed verdict interposed at the conclusion of plaintiff’s evidence. Defendant contends that plaintiff’s evidence showed that plaintiff was obligated by the chattel mortgage to keep the automobile insured at all times with loss payable clause in favor of defendant, to deliver the policy to defendant, and upon failure to comply with said conditions defendant was authorized to procure insurance at plaintiff’s expense; that plaintiff’s evi*278dence showed that he did not deliver such policy to defendant, therefore, defendant properly obtained insurance at plaintiff’s expense. The record reveals that at the conclusion of plaintiff’s evidence, defendant’s counsel moved for a directed verdict for the reason that plaintiff had not introduced any evidence of “any damage.”
[1, 2] G.S. 1A-1, Rule 50(a) provides that a motion for directed verdict shall state the specific grounds therefor. This provision of the rule is mandatory. Wheeler v. Denton, 9 N.C. App. 167, 175 S.E. 2d 769 (1970). We hold that defendant was not entitled to a directed verdict for the reason stated to the trial court; and the reason advanced in this court being different from that advanced in the trial court we refrain from passing upon it.
Defendant contends that the trial court committed error prejudicial to defendant by violating G.S. 1A-1, Rule 51(a), this rule being formerly covered by G.S. 1-180. Specifically, defendant contends that during the trial the judge expressed an opinion on the evidence and that in his charge he gave unequal stress to the contentions of the respective parties. The points are well taken.
The pertinent principle of law was discussed by us in the recent case of State v. Lemmond (No. 718SC445, filed 4 August 1971). Although Lemmond was a criminal case, we think the same principle applies to a civil action.
 It is well settled in this jurisdiction that a trial judge is expressly forbidden to convey to the jury, in any manner, at any stage of the trial, his opinion as to whether a fact is fully or sufficiently proven. State v. Cox, 6 N.C. App. 18, 169 S.E. 2d 134 (1969) and cases therein cited.
 The prohibition provided by G.S. 1-180 in criminal cases and Rule 51 (a) in civil cases does not apply to the charge alone, but prohibits a trial judge from asking questions or making comments at any time during the trial which amount to an expression of an opinion as to what has or has not been shown by the testimony. Galloway v. Lawrence, 266 N.C. 245, 145 S.E. 2d 861 (1965). The trial judge must abstain from conduct or language which tends to discredit or prejudice a litigant or his cause with the jury. State v. Carter, 233 N.C. 581, 65 S.E. 2d 9 (1951). The criterion for determining whether the trial *279judge deprived a litigant of his right to a fair trial by improper comments or remarks in the hearing of the jury is the probable effect upon the jury. State v. Cox, supra.
 The record in the instant case reveals that the trial judge sustained his own objection to some ten questions1 posed by defendant’s counsel to his witness; that the trial judge sustained his own objection to a question asked by defendant’s counsel on cross-examination of plaintiff; and that the trial judge on his own motion struck certain testimony introduced by defendant. The record reveals that the trial judge voiced no objection to any question asked or evidence offered by plaintiff’s counsel.
As was said by us in State v. Lemmond, supra, we recognize the general rule that a trial court, in the exercise of its right to control and regulate the conduct of the trial, may, of its own motion, exclude or strike evidence which is wholly incompetent or inadmissible for any purpose, even though no objection is interposed to such evidence. Greer v. Whittington, 251 N.C. 630, 111 S.E. 2d 912 (1960). Nevertheless, the exercise of such right must be kept within proper bounds. We think this case is analogous to State v. Frazier, 278 N.C. 458, 180 S.E. 2d 128 (1971) where Justice Huskins, speaking for the Supreme Court said: “The content, tenor, and frequency of the remarks, and the persistence on the part of the trial judge portray an antagonistic attitude toward the defense and convey to the jury the impression of judicial leaning prohibited by G.S. 1-180. This requires a new trial.”
 We also think the trial judge violated Rule 51 (a) by giving unequal stress to the contentions of plaintiff. Quoting the record pertinent to this question would serve no useful purpose.
We refrain from discussing the other assignments of error brought forward and argued in defendant’s brief as the alleged errors might not recur upon a retrial.
For the reasons stated, we order a
Judges Morris and Parker concur.